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An Elementary Outline Of Mechanical Processes | by G. W. Danforth



Giving a brief account of the materials used in engineering construction and of the essential features in the methods of producing them, also describing shop processes and equipment for the shaping of metals into forms for engineering and general uses arranged for the instruction of midshipmen at the u. s. naval academy and for students in general

TitleAn Elementary Outline Of Mechanical Processes
AuthorG. W. Danforth
PublisherPhilip R. Alger
Year1912
Copyright1912, Philip R. Alger
AmazonAn elementary outline of mechanical processes

By G. W. Danforth, U. S. Navy Instructor in the Department of Marine Engineering and Naval Construction U. S. Naval Academy, Annapolis, Maryland Annapolis, Maryland The United States Naval Institute

An Elementary Outline Of Mechanical Processes
-Preface
This book is intended as an elementary account of the several classes of processes employed in shaping materials of construction for various mechanical uses. A brief account of the properties of these...
-Chapter I. Introductory. Engineering Materials. 1. Scope Of Mechanical Processes
Mechanical processes properly include every manual and machine process, and the mechanical part of every chemical process, used in the extensive field of the mechanical arts. This broad field includes...
-2. Study Of Processes
Every process involves time, labor, and expense, and is employed in whole or in part only because it accomplishes a definite and necessary purpose. Its use must be justified as a necessary step toward...
-3. General Classification Of Materials
The materials used in all branches of construction are commonly called engineering materials or materials of construction. The most important of these, as iron, steel, brass, wood, stone, etc., are we...
-4. Materials Most Used
The material most extensively used in engineering construction is iron in its several forms, included under three divisions, viz., wrought iron, steel and cast iron. The materials of these three divis...
-5. Properties Of Materials
All materials have certain physical properties which determine their fitness for specific purposes. Of first consideration in materials of construction is strength, or tenacity, which is the attractio...
-6. Influences Which Change Properties Of Materials
Heat has more or less influence in changing these properties in a given material. Hardness and strength are increased by hammering or rolling a metal, and these properties are changed, often in a m...
-7. Fatigue Of Metals
It has been found that metals give way in some cases under smaller loads than they could originally carry. This is called fatigue, and is caused by a very great number of reversals or repetitions o...
-8. Classification Of Forces
Forces acting upon materials are classified according to their direction of action. A force acting on a material is called a stress, and the deformation caused by this action is the consequent stra...
-9. Alloys
An alloy is a combination formed by stirring together two or more metals (occasionally with other substances introduced) in a state of fusion. Investigators state that some alloys are chemical combina...
-10. Peculiarities Of Alloys
Alloys have peculiarities demanding special and extensive study to understand them, and no laws have yet been found by which the properties of an alloy may be determined from the properties of its con...
-11. Designations Of Well-Known Alloys
The most extensively used of all alloys are those consisting mainly of copper. Their ornamental appearance and non-corrosive quality make them desirable, and their strength, with varying degrees of ha...
-12. Brass
This is one of the most important of the alloys. While its usual constituents, copper and zinc, combine in any proportion, the range of useful proportions varies from about 60 to 89% of copper. A w...
-13. The Bronzes
Phosphor, manganese and aluminum bronzes are among the best bronzes known, and are the most extensively used. Bronzes are used when a strong and fairly ductile non-corrosive alloy is necessary in ship...
-14. Other Useful Alloys
Other Useful Alloys in engineering work are: Anti-Friction Metal, used to line bearings for shafts; composed of Best refined copper. . 3.7 per cent Banca t...
-15. Copper. Its Uses
Copper is next in importance to iron as a metal of the useful arts, though it is used mostly in alloys. Its principal uses are: (1) As the main constituent of most of the useful alloys. (2) For ...
-16. Properties Of Copper
The color of copper is dull red. In malleability and ductility, either hot or cold, it ranks very high. Its tensile strength is about 30,000 lbs., although rolling, hammering or drawing it into wire n...
-17. Uses Of Zinc
The principal uses for this metal are as follows: (1) The most important use is for alloying with copper in making brass or composition. (2) When zinc is exposed to air or water, a durable and i...
-18. Properties Of Zinc
Zine has a bluish-white color. Its malleability and ductility are confined to certain narrow limits of temperature, and it must be maintained at a temperature of about 240 F. when it is being rol...
-19. Uses Of Tin
(1) The most important engineering use of this metal is in alloys. (2) It is used extensively for coating sheets of iron to prevent corrosion, and these sheets are widely known as tin ; also it ...
-20. Properties Of Tin
Tin has nearly the whiteness of silver. It is very malleable and flexible, but not elastic. Its tensile strength is too low for it to be drawn into wire. Air will not tarnish it readily, but some acid...
-21. Uses Of Lead
This metal has several minor uses in engineering. Of these the principal uses are: (1) As sheet lead for lining tanks and basins because of its power to resist corrosion from air and from many dilu...
-22. Properties of Lead
Lead has a blue-gray color. It is the softest and heaviest of the common metals. It is very malleable and ductile, but has no elastic strength, and its tensile strength is so low that it cannot be dra...
-23. Uses Of Nickel
(1) A very important engineering use for this metal is in alloy with steel. Its addition to mild steel gives a product of great elastic and tensile strength and fair ductility. Its presence in steel l...
-24. Properties Of Nickel
Nickel is white with a bluish tinge. It is malleable and ductile It has about the same hardness and fusion point as iron, and is heavier than iron, to which it is closely related, having magnetic prop...
-25. Uses Of Aluminum
The principal uses of aluminum are in making aluminum bronze, and as pressed sheet or cast aluminum for various utensils and fittings where extreme lightness and fair strength are required. ...
-26. Properties Of Aluminum
This metal presents a remarkable combination of qualities. It is the lightest of the useful metals (excepting magnesium, which has only limited uses as a metal), has many exceptional uses, is more abu...
-27. Use And Properties Of Antimony
In engineering uses this metal serves as a hardening constituent for anti-friction alloys. It also causes these alloys to expand after they are poured into place, making them fill completely, when col...
-28. Portland Cement. General Characteristics
This material having been perfected within recent years, has many important uses. It is supplied commercially in a very finely ground state, and, when mixed with water alone, or when mixed with water ...
-29. Varieties Of Lime And Cement
The many forms of lime and building cement consist mostly of calcium oxide (CaO), which is formed from calcium Carbonate (CaC03) by calcination. These forms merge one into another according to the kin...
-30. True Cements
When limestone (CaC03) contains clay, the process of calcination produces a compound which, due to the silica in the clay, gives the product the power of solidifying or setting when wet, either unde...
-31. Requisites In Selecting Raw Materials
In any natural materials chosen for the manufacture of this cement, there must be ascertained: (1) The proportions of the required ingredients contained. (2) The kinds and quantities of other in...
-32. Composition Of Cement
It is now established that the essential raw ingredients of Portland cement are limestone, 75 to 77%, and alumina (A12O3) and silica (SiO2) 20 to 25%. The alumina and silica are commonly found combine...
-33. Manufacture Of Portland Cement
A cement manufacturing plant is usually located at or near a natural deposit of the materials composing cement. These materials may or may not be a natural mixture, but in either case chemical analyse...
-34. Uses Of Portland Cement
Cement mixed with water is virtually a plastic stone, and it can be used for many purposes in place of stone with economy in shaping to the form required, and advantage in securing a hard, fire-proof ...
-35. Cement Mixtures
Cement and water alone are known as neat cement, and are seldom so employed except where economy is not considered, or for purposes of maximum strength. For most purposes a mixture of sand, brok...
-36. Method Of Using Concrete
For shaping concrete to a form required, the usual practice is to make a form of planks or timbers, well braced, enclosing the space which the concrete is to occupy. The mixture is carefully made in a...
-37. Causes Of Setting And Strengthening Of Cement
It is thought that the setting of cement is due to the crystallizing of the silicate and aluminate of lime, which, in their dry and anhydrous form after burning, are soluble in water, but which pass i...
-38. Wood. Use As Parts Of Machinery
Very little wood is now used as engine or machinery parts. Metal has displaced wood almost entirely in moving and stationary parts of machines, and in many general uses for which wood was once exclusi...
-39. Lumber And Timbers
Wood for general uses is handled commercially in the form of lumber or timbers. Trees are felled, and that part of the lower trunk free of large limbs is sawed into logs usually a few inches longer th...
-40. Lumber Grading
The several pieces sawed from a log are not of the same quality, but vary more or less in grade. The slabs, covered on one side with bark, and the culls or very unsound pieces, are of no value as lumb...
-41. Hard And Soft Wood Lumber
Hard woods are those cut from the broad-leaf trees (as oak, hickory, poplar), and soft woods are those from the conifers, or needle-leaf trees (as pine, cedar, fir and redwood). ...
-42. Heart And Sap Wood
The wood surrounding the center of a tree is heart wood and outside of this is the sap wood, usually lighter in color than the heart. Sap wood, except in certain trees, as ash and hickory, is less har...
-43. Lumber Inspection Rules
For uniformity in lumber sizes and qualities, certain general rules are adopted by lumber producers, who adopt, also, specific rules for the inspection of each kind of wood according to its uses. Lumb...
-44. Standard Defects
An example of the standardization of lumber defects is given by the following copy of Navy Department General Lumber Specifications. Each one of the following items constitutes a standard defect: (...
-45. Rough And Dressed Lumber
All lumber direct from the saw is rough lumber. After seasoning, the better grades may be re-sawed into smaller pieces and are frequently planed smooth, on one or both faces and one or both edges, by ...
-46. Lumber Measurement
Lumber and timbers are measured and sold by board feet. A board foot has a surface 12 x 12 inches and a thickness of one inch. Boards less than an inch in thickness are regarded as an inch thick in se...
-47. Durability Of Wood
Wood may be preserved indefinitely if kept dry or submerged in still water, and free from attacks of insects. Wood exposed to the atmosphere absorbs more or less moisture. Alternate wetting and drying...
-Chapter II. A General Outline Of Metal-Producing Processes. 48. Ores
The common metals, excepting copper, do not occur free in nature, but are produced from their ores which generally require chemical treatment at high heat in furnaces. Uncombined copper, known as nat...
-49. Elimination Of Gangue
As an ore comes from the mine it is desirable to eliminate at once the gangue. This may be done more or less successfully with some ores by simple hand-picking methods, while other ores must be crushe...
-50. Calcination
Another method of reducing the quantity of impurity before the ore is transported from the mine is by calcination, which consists of heating the ores to a point short of fusion. This drives away moist...
-51. Breaking Up The Ore Compound
The actual metallurgical operation of breaking up the chemical combination of metal with oxygen and with other elements in ores is done by heat in furnaces and is called the dry process; or is done by...
-52. Smelting Furnaces
The step of the process named in item (3) of the preceding paragraph is that of smelting, and is usually carried on in furnaces built of common silica brick for the outer layers, and high grade refrac...
-53. The Blast Furnace
Fig. 6 shows the essential parts of a blast furnace for smelting iron. It is given the name of blast furnace because combustion is maintained by forcing a blast of air through the mass of fuel, ore an...
-54. Blast Furnace Modifications
The principle of the blast furnace as shown in Fig. 6 is applied to the smelting of copper and lead ores, but the furnaces used for these ores are somewhat modified. Iron smelting furnaces vary from 5...
-55. Acid And Basic Ores
The earthy matter of ores consists mostly of silica (sand), silicate of aluminum (clay), limestone, and magnesia. All of these are seldom found in the same ore, but almost all ores contain (1) silica ...
-56. Fluxes
The usual operations of smelting require that an ore shall always be mixed with a flux. The ore is either acid or basic, and the flux must be either basic or acid, opposite to the character of the ore...
-57. Blast Furnace Operation
This description applies particularly to iron smelting, but it is also the essential part of blast furnace operation for smelting other ores. The starting of a blast furnace in operation is called bl...
-58. The Blast Stove
In blast furnace smelting of copper and lead, the gases passing from the top of the furnace do not contain much gas which will burn, hence they are allowed to escape, but in the iron smelting furnace ...
-59. Reverberatory Furnaces
Two types of the reverberatory furnace are used in smelting. Fig. 9 shows a roasting furnace in which ores are roasted to simplify them before they are placed in the melting furnace shown in Fig. 10. ...
-60. Atmosphere Of Reverberatory Furnaces
These furnaces may be so fired and the air supply to the fire so regulated as to make the furnace action oxidizing or reducing. Oxidation demands (1) an excess of air beyond that needed for complete o...
-61. Refractory Materials
An important feature demanding particular attention in all furnaces is the interior lining, because of the intense heat and the chemical action to which furnace linings are subjected. A lining must (1...
-62. Sources Of Copper
The greater part of the world's supply of copper is produced by smelting the sulphide ores. A very extensive source of supply of native copper is the Lake Superior deposit. Only a small supply of copp...
-63. Producing Copper From Its Sulphides
In the smelting process, which is preceded by roasting the ores to remove some of the sulphur, large lump ores not too complicated with gangue and other metals, are smelted in the blast furnace, while...
-64. The Poling Process
This consists of melting blister copper in a reverberatory furnace and stirring it to bring about the chemical action necessary to remove the remaining impurities. A charge is melted under the heat...
-65. Electrolytic Refining Of Copper
The malleability of copper and its efficiency as a conductor of electricity are greatly reduced by even the slightest impurities in the metal. The electrolytic process of refining is used because it g...
-66. Zinc
Zinc is obtained from the sulphide, or blende; and to a smaller extent from the carbonate and oxide. There are several complex zinc ores, and some of these, as the zinc and lead sulphides, are abund...
-67. Tin
Tin is produced from its oxide (SnO2) known as stannite, casserite, or tin-stone, which is not so abundantly distributed as are ores of many other metals. The oldest mines are in England and the East ...
-68. Lead
Lead is produced mainly from its sulphide, known as galena. The smelting of this ore is complicated by the presence of arsenic, copper, iron, zinc, or silver, and like the smelting of copper sulphides...
-69. Nickel
Nickel is produced from the arsenide, known as kupfer-nickel, and to a lesser extent from the sulphide. The smelting process is somewhat complex and is accomplished by roasting, reducing in presenc...
-70. Aluminum
Aluminum never occurs free in nature, but no other metal known, not excepting iron, occurs in such abundance in its compounds, nor is any other metal so widely distributed over the earth. Its combinat...
-71. Electricity In Metallurgy
Electrolytic action has long been applied to electro-plating, and in recent years to the refining of copper. The combined electrolytic and heat actions of current are used in producing aluminum, and v...
-Chapter III. Fuels. 72. Uses
The use of fuels of different kinds is highly essential in the various industries for the producing and shaping of metals. Heat is indispensable (1) to bring about chemical action which breaks up the ...
-73. Combustion
The economical use of fuel requires that none of it should be wasted in an unburned state, as is frequently the case in the escape of unburned gases up the chimney. Combustion is the chemical union of...
-74. Components Of Fuels
The heat-producing elements, i. e., the combustible substances, of all fuels, whether solid, liquid, or gaseous, are carbon and hydrogen. Many fuels, particularly coal, contain free sulphur, which is ...
-75. Classes Of Fuel
The following classification includes all fuels in general use in the arts and industries. Some of these have but limited and special uses in the metal industries. (1) Solid Fuels. (a) Natural F...
-76. Wood And Charcoal
Wood is less and less used as fuel because of its increasing scarcity and because coal is abundant and easily handled. Charcoal, made from wood, is now used only for special purposes because of its hi...
-77. Coal
Coal is the most extensively used of all fuels. The different varieties of coal, with many different names, merge one into another, and the fundamental distinction between the several varieties is the...
-78. Coke
Coke is a product of bituminous coal, bearing the same relation to coal which charcoal bears to wood. The better varieties, made from the softer bituminous coals, and used almost entirely in the blast...
-80. Powdered Coal
Powdered Coal has a limited use in metal heating furnaces. It is ground to a fine dust by revolving it in a steel drum with hard pebbles. It is then conveyed through tightly made sheet iron tubes to t...
-81. Screenings. Briquettes
In handling coal at the mine, a considerable quantity becomes pulverized. In this form it is known commercially as screenings. This is now used in mechanical stokers fitted to steam boilers, and some ...
-82. Liquid Fuels
The only practicable cheap liquid fuel is mineral oil, better known as crude petroleum, though this is confined to too few localities for general displacement of coal, but in those localities is usual...
-83. Gas Fuels
The great convenience of natural and producer gas as fuel in reverberatory, steel-making, and metal-heating furnaces has caused extensive use of gas fuel in all metal industries. For furnace use a ...
-84. Natural Gas
Natural Gas, like mineral oil, is obtained from cavities in which it is confined in the earth. It is abundant in a few localities only, but the great desirability of gas has given rise to the artifici...
-85. Producer Gas
Producer Gas is made as follows, referring to the gas producer in Fig. 13. A shell of steel plates, lined with fire-bricks, rests on a cast-iron ring A, which in turn is supported by lugs resting on t...
-86. Water Gas
Water Gas is produced by forcing steam through a network of very hot fire bricks, on the principle of the blast stove, and immediately, while at a high temperature, through a bed of incandescent fuel....
-87. Illuminating Gas
Illuminating Gas is made in closed retorts from coals rich in gas, and is too expensive for extensive use as fuel in mechanical industries. ...
-Chapter IV. Iron And Steel. I. Iron Ores and Their Reduction. Pig Iron. 88. Iron Ores
These ores are very widely distributed and very abundant in nature, but many deposits cannot be worked profitably. According to chemical composition, ores available for smelting may be classified as f...
-89. Preliminary Preparation Of Iron Ores
Upon taking iron ore from the mine, which is usually a simple process of excavating after surface earth is removed, it is desirable to remove the gangue, if this exists in large quantity, to avoid the...
-90. Calcination
The main results of calcination, and the consequent advantages in smelting are, for iron ores: (1) Driving off water and thus avoiding interference with the regularity of the smelter fire. (2) E...
-91. Reduction
Iron ores are always reduced in the blast furnace, the parts and operation of which have been described (Pars. 53 and 57. The process of smelting iron is very simple, as the ores used are oxides, unco...
-92. Pig Iron
The product of the blast furnace is pig iron. From this all other forms of iron and steel are now made. Some grades of pig iron are selected, and without further change are merely re-melted in the fou...
-93. Disposition Of Iron From The Blast Furnace
When iron is tapped from the furnace, it is the practice at present to convey it by means of a trough or trench into a large ladle, even if it is to be cast into pigs. Fig. 16 shows iron flowing along...
-94. Grades Of Pig Iron
The grade of iron which a furnace is producing is governed within certain limits by the chemical makeup of ore, fuel, and flux, but the composition of these elements of the charge is not always unifor...
-95. The Three General Classes
It is essential to understand the difference between the several classes of iron and steel, and the effects of the substances which they always retain from the blast furnace. These substances are freq...
-96. Carbon In Iron
When iron is fused in smelting, it gets its first carbon, the amount depending upon its temperature, and upon the manganese, silicon and other substances present in the furnace. This amount increases ...
-97. Silicon In Iron
Cast iron ordinarily contains silicon up to 4% or slightly more, although silicon pig. the form in which silicon is handled for foundry and similar uses, is made in the blast furnace containing up t...
-98. Sulphur In Iron
This element is particularly objectionable, but is always present in iron and steel, rendering them brittle when hot, a condition known as red short or hot short. Iron and steel for high-grade for...
-99. Phosphorus In Iron
Neither the quantity of carbon dissolved in iron nor its condition as combined or uncombined carbon is much affected by phosphorus, but this element has the effect of hardening iron slightly. It is, h...
-100. Manganese In Iron
The smelting process always leaves in iron a small amount of this element. Up to 2% it increases tenacity and hardness, but beyond that amount it causes brittleness. It tends to eliminate sulphur and ...
-101. Properties Of Cast Iron
Cast iron is brittle, non-elastic, and the easiest fused of all iron, these properties varying directly with the amount of combined carbon and to a less degree with the amount of uncombined carbon con...
-102. Properties Of Wrought Iron
In composition, wrought iron differs from cast iron and steel in two important features, viz.: (1) In having had removed, as an essential of its manufacture, the greater part of the five elements usua...
-103. Properties Of Steel
When steel first came into practical use, its distinguishing characteristic was its ability to harden if heated to a red heat and cooled suddenly, as in water or oil. Present methods of steel making h...
-104. History Of Wrought Iron
Wrought iron is the form in which iron was probably first known to man. The ancients reduced it directly from the oxide ores in small furnaces, using charcoal as fuel and depending at first for a blas...
-105. Methods Of Production
This method of producing wrought iron direct from the ore is called the direct method. It it still used to a small extent in a few places in Europe where charcoal is cheap, but its output is not impor...
-106. The Indirect Process Of Wrought-Iron Making
This process consists essentially of the following steps, viz.: (1) Melting pig iron in a form of reverberatory furnace called a puddling furnace, and burning out the impurities principally by oxyg...
-107. The Puddling Furnace
Fig. 18 shows two sections of a double puddling furnace, built double to save space, building material and heat. This furnace is built of common brick, and lined with refractory brick. It is held toge...
-108. Puddling-Furnace Operation
Having prepared the hearth and brought the furnace to a good heat, a charge of about 1500 lbs. of pig iron is thrown in at the working door, and with it is charged a quantity of cinder or squeezer sca...
-109. Treatment Of Puddle Balls
The furnace treatment just described burns out almost all of the usual impurities in iron, but this treatment produces a slag or cinder of iron oxide and silica which mixes with the iron and forms a s...
-110. Re-Heating And Welding Muck Bar Into Wrought Iron
Muck bar still contains too much cinder and is too lacking in homogeneity for use. Fig. 22. - Re-heating Furnace used in Making Wrought Iron. When cold, it is cut into lengths of about 3 1...
-111. Rolls For Shaping Wrought Iron
Fig. 23 shows the general type of rolls used for wrought-iron piles. This machine is very simple, and consists essentially of three chilled cast-iron rolls A, B, C, mounted in a frame DD (called the h...
-112. History Of Steel
The first known steel was possibly produced accidentally by the primitive method which smelted wrought iron direct from the ore. The increase of the degree of heat in the primitive smelting furnace ca...
-113. The Cementation Process
By this process, wrought-iron bars are converted into steel. Alternate layers of sifted wood charcoal and iron bars are placed in fire-brick basins or pots.' the tops of which are made air tight wit...
-114. Present Processes Of Steel Making
At present there are in extensive use three processes of steel making. These are, in order of the annual quantity of steel produced by each: (1) The Bessemer process. (2) The open-hearth process...
-115. The Bessemer Process
This process converts pig iron into steel by blowing cold air through the molten metal to burn out the carbon. After the carbon is removed (and incidentally some other impurities are removed), and the...
-116. Operation Of The Converter
The essentials of operating an acid converter are here given. The operation for the basic method is but slightly different. After the converter has been emptied of a charge, the vessel is revolved ...
-117. Pouring The Steel Into Moulds
The ladle is at once conveyed by the crane to a row of large cast-iron ingot moulds, and the metal is poured, or teemed, into them as shown in Fig. 25. Most large ladles are now poured from a hole i...
-118. Features Of The Bessemer Process
Pig iron of a certain range of composition must be selected for this process. It must not contain more phosphorus nor sulphur than is allowable in the steel, as these elements are not burned out in th...
-119. The Open-Hearth Process
This and the Bessemer process convert pig iron into steel by first burning the impurities from the molten iron, but the equipment used in the open-hearth process differs considerably from that used in...
-120. The Open-Hearth Furnace
This is a reverberatory furnace to which is connected a regenerative system of heating. A longitudinal section of a furnace, lined for the basic process, is shown in Fig. 26, and the diagram below the...
-121. Charging The Open-Hearth Furnace
The capacity of the average open-hearth furnace is about 60 tons of metal. Supposing the furnace to be at a moderate heat, ready for the charge, the tapping hole, which leads from the lowest part o...
-122. Operation Of The Open-Hearth Furnace
The purpose of this operation is to remove, so far as can be done by the process, the silicon, manganese, carbon, phosphorus and sulphur in the charge. The removal of sulphur is difficult and uncertai...
-123. Tapping Out
It requires from 6 to 9 hours to bring a charge to the condition for tapping out. In this condition the bath of slag-covered metal contains some iron oxide and more or less oxygen, carbon monoxide, or...
-124. Pouring The Moulds
When all the slag has flowed from the furnace, the crane lifts the ladle and carries it while the steel is teemed into the moulds, just as shown in Fig. 25. Small pieces of aluminum are thrown into ea...
-125. The Talbot Process
This is a continuous open-hearth process, and seems destined to fill an important place in steel production. The furnace used embodies the same principle as the ordinary open-hearth furnace, but it is...
-126. The Duplex Process
This is merely a combination of the Bessemer and open-hearth processes. Pig metal is blown in an acid Bessemer converter until silicon, manganese, and part or all of the carbon are removed. It is t...
-127. Uses Of Open-Hearth Steel
Open-hearth steel combines the two requisites of (1) a very reliable steel made in large quantities, and (2) moderate cost of production. Steel made by this process is used for bridge material, ship p...
-128. The Crucible Process
The method of melting steel in crucibles or pots was brought into use as a means of improving the product of the cementation furnace, as mentioned in Par. 113. The introduction of the Bessemer and the...
-129. Materials Used In Crucible Steel
Crucible steel is made principally from steel scrap, with which is combined cast iron if the carbon is to be increased, or muck bar if the carbon is to be lowered. All of these materials are of known ...
-130. Crucibles
In America, crucibles are made of a mixture of half graphite and half fire clay, carefully kneaded, and moulded compactly by hand to shape as shown in Fig. 29. After they are moulded, they are allowed...
-131. The Crucible Furnace
Modern crucible steel furnaces are heated with natural or producer gas by the regenerative system, though many coke-heated furnaces, similar to a brass-melting furnace, are still in use. Fig. 30 shows...
-132. Charging A Crucible
A memorandum directing the superintendent of the crucible department to make a particular grade of steel gives him the analysis of what the steel must contain. From the several bins are selected su...
-133. Operation Of The Crucible Furnace
After the regenerators have brought the furnace up to a high heat, the charged crucibles are lowered one by one into the melting holes. The chimney draft prevents flame from coming out of the melting-...
-134. Properties Of Crucible Steel
The reason for the superiority of crucible steel over steel of like composition from other processes is not always apparent, but is no doubt due in greater part to the following conditions, viz.: (...
-135. Special Steels
Iron will alloy with most metals, and some of these alloys have been highly developed for special purposes. These alloys are all alloys of steel and a small per cent of another metal. The metals most ...
-136. Ingot Moulds. Stripping Ingots
The usual form of ingot mould for Bessemer and open-hearth steel is shown in Fig. 32, which shows three moulds sitting on a common base of heavy cast iron carried by an ingot car. Fig. 33 shows a long...
-137. Impurities In Steel. Segregation
Besides carbon, which determines hardness, steel contains a trace or more of manganese, silicon, phosphorus and sulphur, which came to it from the ore, or during the various stages of manufacture. Tra...
-138. Defects In Steel Ingots
Besides the presence of gas bubbles, and the result of segregation in a steel ingot, there are other defects which result from the pouring and cooling of the ingot in the mould. A mass of molten me...
-139. Fluid Compressed Steel
Many efforts have been made to improve open-hearth and Bessemer steels, with the view to having them approach crucible steel in quality without having its high cost of production. One of the method...
-140. Compressing Steel
The method of compressing steel is briefly as follows: On a specially built car not unlike an ingot car is placed a large cylindrical mould built up of very heavy cast-iron sections, one of which is s...
-141. The Electric Refining Furnace
Another method of improving the quality of steel, recently perfected, is that of electric refining. This method seems destined for a wide range of usefulness in steel making, as it does more than the ...
-Chapter V. Mechanical Treatment Of Metals. Heat Treatment Of Metals. 142. Forms Of Newly Produced Metals
The common metals are taken in a molten state from the furnaces which produce them and are cast into the forms outlined in this and the following paragraph. It must be mentioned that most of the pig i...
-143. Primary Outline Of The Shaping Of Metals
It will be seen from the preceding paragraph that all objects made of iron and steel may be divided into two general classes in regard to the methods of shaping them. These are: (1) Objects poured ...
-144. Reducing An Ingot To Marketable Forms
An ingot stripped from its mould should go while hot to the soaking pit, a large furnace in which it is placed to be brought to a red or yellow heat preparatory to rolling. From the soaking pit it is ...
-145. Reheating Of Ingots. The Soaking Pit
Although the stripped ingot may be at a glowing red heat as it comes from the mould, it cannot be rolled because the interior is yet liquid and the solid exterior would merely disrupt and allow the li...
-146. Rolling An Ingot
When an ingot has reached the temperature for rolling, it is lifted from the pit and carried by the crane to the ingot buggy, where it rests until a lever is released to dump it on the roller table. T...
-147. Mill Scale
In heating an ingot in the pit, particularly in an oxidizing flame, and in exposing the red-hot ingot to contact with the atmosphere, a film of iron oxide forms over its surface. This oxide is very br...
-148. Structural Steel Shapes
The use of mild steel for structural purposes, i. e., bridge building, ship building, architectural structures, railroad and other rails, etc., has developed certain standard shapes especially for the...
-149. Types Of Rolling Mills
The number of rolled products now common in the iron and steel trade, consisting of blooms, billets, structural shapes, plates, rails, bars, rods, etc., necessitates rolling mills of a variety of type...
-150. The Cogging Mill
Fig. 43 shows a cogging mill, so named because its rolls are roughed or cogged to grip the end of the ingot firmly and force it into the rolls. The blooming mill in Fig. 40 does the same kind of work....
-151. The Structural Mill
Fig. 44 shows a universal, reversible, structural mill. This mill has two horizontal rolls CC, and two vertical rolls DD. The mill shown in this view is for rolling large I-beams, and the vertical rol...
-152. The Billet Mill
Fig. 45 shows a three-high billet mill. Each of the rolls of this mill runs continuously in one direction as shown by the arrows. To allow a bloom (or a small ingot) to be run between the upper and mi...
-153. The Rail Mill
Fig. 46 shows the several mills for shaping railroad or street-car rails. These are three-high mills. Fig. 46. - Rail Mill. The blooming mill first breaks the ingot down to about 8 x 8 inc...
-154. The Sheet-Bar Mill
Thin sheets of iron or steel are rolled hot from bars about 8 inches wide known as sheet-bars. The sheet bars for this industry are rolled in the sheet-bar mill, not unlike the billet mill in Fig. 45,...
-155. Plate Mills
Slabs from the blooming or slabbing mills are reheated and rolled by the plate mill into plates for many uses, including boiler plates, ship plates, tank plates, etc. Plate rolling was described un...
-156. Names Of Rolling-Mill Parts
The more commonly designated rolling-mill parts include rolls, housings, roller table, manipulator, guides, guards, passes, and collars. Several of these parts have been mentioned. Fig. 47 shows th...
-157. Reheating Of Blooms, Slabs And Billets
Reheating furnaces are of many forms according to the fuel used, the size and shape of the material to be reheated, and the rapidity demanded in handling the heated material. The largest types of rehe...
-158. Reheating Furnace For Large Blooms
Fig. 51 shows the front of a regenerative heating furnace for blooms and other large material, with the charging crane used to handle heavy material. This furnace is modeled like the open-hearth steel...
-159. Precautions In Reheating High-Grade Steel
To avoid the formation of scale in reheating metals, i. e,, the waste of the surface by oxidation, the furnace flame should be a reducing and not an oxidizing flame. No risks of oxidation can be taken...
-160. Points For The Inspection Of Rolled Material
Steel may be good or bad in quality due to the substances it contains, and steel which is good when tapped from the furnace may be made bad by subsequent casting, reheating and mechanical treatment. R...
-161. Effect Of Mechanical Treatment Of Metals
The pressure of the rolls and the impact of the forging hammer on a piece of metal increase the strength of the metal from 2 to 5 times, according to the composition, the degree to which the metal is ...
-162. Cold-Rolled Steel
The colder a metal is when rolled or hammered, the greater the resulting hardness. The depth of the hardness depends upon the depth to which the rolling or hammering pressure penetrates. There is e...
-163. Large Forgings
Many massive steel products, as armor plate, large gun parts, and large shafting for marine engines or turbines, cannot be rolled because of their shape, or because their size makes rolling far more e...
-164. The Hydraulic Forging Press
Fig. 52 shows a press for heavy work. The diagram in Fig. 53 shows the interior features of the press. This equipment consists of the press, the hydraulic intensifier, and the auxiliary water tank....
-165. Handling Large Ingots For Forging
Special equipment must be installed to transport large ingots between the reheating furnace and the forging press and to hold them for the work of forging. The furnace and the press are located conven...
-166. The Heat Treatment Of Metals
An essential part in the mechanical shaping of a metal is the heating required to make it easily workable without injury to its strength and other properties. Heat treatment includes all heating from ...
-167. Changes In Steel Due To Heating
It is necessary to heat steel not only to shape it, but to anneal and harden it. That heating for any of these purposes may be properly done, it is necessary to understand certain peculiarities, parti...
-168. Annealing Of Metals
When a metal is heated to unequal degrees throughout its mass, or the parts of the mass are cooled at different rates, as is common with large forgings or large castings, or when hammering, rolling, o...
-169. The Hardening Of Steel
Steels containing above .25% of carbon (approximately) will become hardened if heated to or above the absorption point and suddenly cooled, in water or by other means. The degree of hardness depends u...
-170. Oil Tempering Of Steel
Much medium-carbon steel is alloyed with nicked, chromium or vanadium to provide material of superior strength and elasticity for moving parts of marine engines, automobile parts and other fittings wh...
-171. Rolling Sheet Copper. The Sheet Mill
For the manufacture of sheet copper, the metal is cast either direct from the refining furnace, or from remelted pigs, into flat cakes 3 or 4 inches thick. As soon as these cakes have set they are d...
-172. Rolling Of Sheet Brass
Brass of the usual compositions is rolled cold into sheets or other forms because the metal will not roll hot. However, if the brass contains less than about 62% of copper it may be rolled hot. In ...
-173. Extruded Brass
The process of extrusion produces brass and bronze shapes similar to rolled shapes. Shapes of more complicated cross section can be produced by the extruding process than by rolling. Many brass and br...
-174. Extruded Shapes
Fig. 57 shows cross sections of some of the shapes produced by this process. Besides the four shapes of bars at the top there are shown a few special shapes as follows: Fig. 57. - Extruded Sh...
-Chapter VI. The Re-Manufacture Of Metals. 175. Scope Of Metal Re-Manufacturing
This branch of metal working includes a great variety of manufacturing industries which shape metals for final uses. In general, the re-manufacture of metals includes all processes which start with ro...
-176. Tool Making
One of the most important branches of re-manufacture is that of tool making. Nearly all tools are made of steel. Those used for measuring and trying, such as calipers, gages, squares and scales, are s...
-177. Special Methods Of Heating And Hardening Steel Articles
In the older methods of heating, hardening, tempering and annealing steel, results depend entirely upon the eye and practice of the workman. To insure uniform results, various methods of heating and h...
-178. Sheet Iron
This product is familiar in many forms. Most of the so-called sheet iron of to-day is sheet steel and not wrought iron as it was before the days of mild steel. This sheet steel for common uses is a ve...
-179. The Manufacture Of Sheet Iron
Sheet iron (as it is commonly known) is made by rolling sheet-bar into thin sheets, as was stated in Par. 154. At the sheet mill, the operation of rolling sheets is as follows: The 30-foot sheet-ba...
-180. Galvanizing
This consists of covering articles of iron or steel with a coating of zinc for the purpose of resisting corrosion. Articles to be galvanized must first be pickled in a dilute acid to remove or loos...
-181. Tinning
Tinning, like galvanizing, is a practical method of coating iron and steel to render it non-corrodable. Tinning gives a smoother, brighter and better-looking surface, and it forms a more durable coati...
-182. The Manufacture Of Tin Plate
This process is very similar to the process of galvanizing, but is more elaborate, and requires more care, as the product is used where resistance to corrosion is more essential. Sheets to be tinne...
-183. Terne Plates
This is a grade of tin plate used for roofing. Terne plates are slightly heavier than tin plates and are much cheaper, as they are covered with a mixture of about 25% tin and 75% cent lead. Many tin v...
-184. Russia Iron
This name is applied to sheet iron of very highly polished or glazed surface also known as planished iron. It is used for protecting the lagging of engines and boilers and for other uses where a no...
-185. Wire Drawing
Metals to be made into wire are first cast (or rolled in the case of wrought iron) into long square billets. A billet intended for wire is about 4 x 4 x 56 inches. Brass and copper billets are also ca...
-186. Gaging The Sizes Of Wire
For designating the diameters of wire, thicknesses of sheet metals, and thicknesses of the walls of tubes, various arbitrarily chosen scales of sizes are used in America and in Europe. These sizes are...
-187. Coating Wire For Protection From Corrosion
Most of the iron wire of to-day is made of low-carbon steel, which corrodes very quickly. The cheapest protection is galvanizing, though tinned or coppered wires are more effectively protected. Gal...
-188. Hard Wire. Spring Material
Drawing hardens wire and the hardness differs in degree according to the composition of the wire and the amount of reduction without annealing. Wire which is not annealed after drawing is called benc...
-189. Pipes And Tubes
These two words are much confused in their applications. Commercially, there are many kinds of pipes and tubes of many sizes and materials. The pipe and tube-making processes described in the follo...
-190. The Manufacture Of Welded Pipe
Most of the welded pipe is now made of a low-carbon acid Bessemer steel. This steel will weld readily, and it has nearly displaced wrought iron for this use. Billets are rolled into skelp (which is...
-191. Defects In Welded Pipe
Besides defective welds, the following named defects in welded pipes, with their causes, may be mentioned: (1) Cracks or Seams. - These originate in the ingot as blow holes, shrinkage, cracks or ot...
-192. Iron Pipe
Welded pipe is commonly seen and much used as steam, gas and water pipe, and is commercially known as iron pipe. It is made in standard sizes designated in inches as follows, viz.: 1/8, 1/4, 3/8, 1/2,...
-193. Seamless Tubes
It is not commercially practicable to produce a welded tube which shall uniformly have the same strength at the weld as in other parts of the metal. The temperature to which it is necessary to heat th...
-194. Piercing Billets For Seamless Tubes
This first operation in making seamless steel tubes begins with small ingots supplied by the rolling mill, free from surface flaws. These ingots are heated and rolled into cylindrical form, and are sa...
-195. Rolling Pierced Blanks
This operation is done by two grooved rolls. Fig. 68 shows a plan view of this machine with the upper roll removed. These rolls force the tube over a fixed mandrel A supported between the rolls by ...
-196. Cross Rolling
This work is done in a reeling machine, the principle of which is shown in Fig. 69. Fig. 69. - Making Seamless Tubes. Tube Reeling Machine. Supposing the axis of the tube to lie in the pla...
-197. Sizing
This is done by a small two-high rolling mill the rolls of which have circular passes of two sizes. The first pass reduces the tube to within 1/32 of an inch of the finished diameter and the second pa...
-198. Straightening And Cutting To Length
After sizing, the tube is transferred to a machine which consists essentially of a pair of cross rolls as shown in Fig. 70. The axes of these rolls, BC and DG, are inclined at equal angles on each sid...
-199. Cold-Drawn Tubes
Tubes can be produced from 2 to 6 inches outside diameter by the hot finishing process. When necessary to produce (1) tubes of less than 2 inches diameter, or (2) larger tubes requiring the smoothest ...
-200. Brass And Copper Tubing
The same methods of piercing and cold drawing described for making steel tubes are used to make tubes of copper and brass. Billets of brass are sometimes turned in a lathe to remove the rough outer su...
-201. Tubes Of Thin Walls And Small Diameters
A tube may be cold drawn over a mandrel, as previously described, until its wall is too thin to stand further pulling through the die. If the tube wall is to be made thinner, further drawing is done b...
-202. Defects in Seamless Tubes
(1) Snakes are small surface cracks developed from surface cracks of the ingot. They are elongated in rolling, and are very small and hard to detect. They are more common in rolled plates than in tube...
-203. Hot-Drawn Seamless Tubes
For producing seamless tubes larger than 6 inches outside diameter, a hot drawing process is used. In this process a plate of the required thickness is punched or sheared into a circular disc. This di...
-204. Steel Cylinders For Storage Of Gases
From the hot-drawn steel tubes just described are made seamless-steel cylinders for Fig. 80. - Reducing the Opening in a Hot-Drawn Tube storage of gases under pressure. The bottom is left on ...
-205. Cold Pressing Of Metals
The ductility of many metals, including many of the alloys, is sufficient to allow sheets of the metals to be pressed cold, without injury, into a great variety of forms. A considerable change of shap...
-206. Steps In Shaping Articles From Sheet Metals
Fig. 81 shows the steps in the process of shaping a vessel from tin, brass, copper or. other sheet metal. The first step is to stamp out the disc, No. 1, from the flat sheet, called cutting or blankin...
-207. Drop Forgings
The process of forging small articles of iron on the blacksmith's anvil is well known. Hand work of this kind is very expensive for making intricate shapes and is a slow process even for making simple...
-208. The Drop Hammer
Fig. 8-4 shows a type of drop hammer such as is used for making drop forgings. The lower die is held on the anvil A and the upper die is held under the hammer B, by keys in the dovetails shown. The di...
-209. Drop-Forging Dies. Making A Drop Forging
Dies for drop forgings are made of hardened forged steel, of cast steel or, for roughing out large work, they are made of chilled cast iron. Dies are made in pairs, as shown in Fig. 85. The lower cont...
-210. Bolts, Nuts And Rivets
Bolts, rivets and nails are pressed into shape, and nuts are punched, by machines specially built for this work. Fig. 90 shows the general arrangement of a machine for pressing bolts, rivets and wi...
-211. Screw-Cutting Machines
These are machines of ingenious design which make a great variety of small metal objects from round, square, hexagon or other shaped rods of brass, bronze and steel. They embody a very high degree of ...
-212. Examples Of Work From The Screw Machine
Fig. 92 shows a variety of small articles made on screw machines. The sizes of these articles vary in length from a fraction of an inch to more than two inches. The specimens shown are pointed to the ...
-Chapter VII. Shops Of Machinery Building And Repairing Plants. Drawings For Shop Use. 213. Distinctive Features Of Building And Repairing Plants
The building of ships, engines, locomotives, machine tools and large machines for a great diversity of purposes necessitates bringing together the products of several different shops. While each of th...
-214. Shops Composing A Building And Repairing Plant
The important shops of a large building and repairing plant are: (1) The Woodworking shop, including the Pattern and the Joiner shops, sometimes separate. (2) The Foundry. (3) The Blacksmith ...
-215. The Drawing Room
When a designer has. determined upon the action, position, form and material of each part of a machine, his ideas are sent to the drawing room in one or more sketches. From these an assembled drawing ...
-216. Drawing-Room Methods
Assembled and detail drawings are first made in pencil on a quality of heavy white or straw-colored paper which will stand considerable erasing. A sheet of tracing cloth is placed over this work, when...
-217. Shop Drawings
The shops must be supplied with drawings of any piece of machinery to be made, as guides to the workmen. These drawings are usually blue or black prints made from the tracings, as mentioned in the pre...
-218. Methods Of Representing Articles On Drawings
Figures 93 and 94 are examples of two methods of showing an article on a drawing. The former is the orthographic method which shows three views projected upon three planes of reference as used in desc...
-219. Consecutive Order Of Shop Work
It is a part of the work of the designer of any mechanical structure or machine to determine not only the material of which each piece of the structure is to be made, but the general method of making ...
-Chapter VIII. The Pattern Shop. 220. Work Of The Pattern Shop
This shop is a woodworking shop devoted to the making of wood patterns for the foundry. These patterns are used as models for shaping moulds of articles to be cast from molten metals. A pattern mak...
-221. Pattern-Shop Equipment
The woodworking appliances which compose the pattern-shop equipment may be divided into (1) power tools (machine tools driven by power), (2) hand tools, and (3) accessory appliances such as work bench...
-222. Power Tools
Machines of this kind are, in all kinds of shops, labor-saving devices. While many such machines might be omitted from a shop equipment, the time and cost for turning out work without them would be gr...
-223. The Circular Saw
Fig. 95 shows a type of circular-sawing machine such as is used for pattern-shop work. This machine consists essentially of (1) a frame which carries the saws, saw mechanism and table; (2) a flat-topp...
-224. The Speed Lathe
This is the common designation for a small wood-turning lathe, which turns at high speed. As the cutting is done by hand tools, this lathe is sometimes called a hand lathe. Fig. 96 shows a view of thi...
-225. Turning Tools
Fig. 99 shows the turning tools ordinarily used with wood lathes. Naming from left to rigid they are: (1) Round-nose chisel. (2) Flat scraping chisel. (3) Gouge. (4) Diamond-point chisel. ...
-226. The Wood Lathe
This designation is given to the pattern-shop lathe for turning large work. It embodies the same features as the small lathe, and is operated in the same way. Hand tools may be used for cutting, or...
-227. The Face Lathe
This lathe consists merely of a head stock mounted for carrying a large face plate. It is used for turning flat work of large diameter. This type of lathe is shown in Fig. 101. Fig. 101. - Fa...
-228. The Band Saw
This machine is shown in Fig. 102. It is used for sawing along straight or curved lines, and may be used for light or heavy work, according to the size of the saw on the machine. Several saws are prov...
-229. The Hand Planer
This machine, shown in Fig. 103, is also known as a jointer. It is used to cut the face or edge of a board to a plane surface, to chamfer corners, to gain, check, plow, match, etc. Board edges and par...
-230. The Surface Planer
This machine is constructed with the same method of cutting provided for the hand planer, but it is a much heavier machine, and is used for surfacing rough boards and timbers. Its table is made in one...
-231. The Boring Machine
This machine is used for boring holes, and consists essentially of a round spindle held horizontally or vertically in suitable bearings. The spindle carries a bit or auger and is made to revolve rapid...
-232. The Mortise Machine
This machine is used to cut square or rectangular holes in wood. It consists essentially of a vertical shaft which is made to oscillate in the direction of its length, and which carries a heavy chisel...
-233. Hand Tools
The hand tools of pattern making are more or less familiar as those used in carpentry work. Attention will be called to a few special tools and features. Saw Teeth. - In sharpening saw teeth, the f...
-234. Materials Used For Patterns
The usual and best adapted material for patterns is wood, although a great many foundries which make large quantities of one article use patterns made of brass or other metals, to avoid excessive wear...
-235. Joints And Cuts In Woodworking
Ripping is sawing wood along the grain. Cross cutting is sawing across the grain. A warped board is said to be out of wind. It may be planed straight in the planer if only moderately out of wind...
-236. Essential Features Of Patterns
A pattern must serve the purpose of making a mould which, when filled with molten metal, will produce a casting of a certain form and size. It would at first thought appear that to serve this purpose ...
-237. Shrinkage Allowance
Metals contract more or less in cooling; hence when the molten metal which fills a mould begins to cool, it also begins to contract, and when cold the casting is smaller than the mould. To obtain a ca...
-238. Drawing A Pattern From The Mould
After the sand is packed about the pattern in a mould, the pattern must be withdrawn before the mould can be filled with metal. In determining how a pattern shall be built, the first consideration is ...
-239. Core Prints And Core Boxes
A hollow, recess, or cavity in a casting is usually made by means of a baked-sand core. This core is placed in the mould after the pattern is removed. It occupies the space to be made hollow and is su...
-240. Fillets
Sharp angles caused by the meeting of surfaces in different planes should be avoided in solid metal work wherever possible. A sudden change in the direction of a surface, causing a sharp angle as at B...
-241. The Prevention Of Warping
Intricate patterns, whether small or large, must be made of several pieces of wood so joined together by glue that the tendencies of the several pieces to warp may be counteracted. This is accomplishe...
-242. Marking And Preserving Patterns
It is very essential to shellac or varnish wood patterns to keep them from absorbing moisture from the sand of the mould. This smooth coating also assists in drawing them from the mould. After appl...
-243. Pattern-Shop Accessories And Methods
Experience in pattern building has brought into use a number of helpful appliances and methods which greatly assist efficiency and rapidity of work, and which are mentioned specifically in this and th...
-244. The Laying-Down Board
Adjacent to each bench is a large drawing board, about 6 x 8 feet in size, made of clear soft wood of sufficient thickness to be rigid, and conveniently supported. When the pattern maker receives f...
-245. The Marking-Off Table
The building of patterns and finishing them accurately to shape is greatly assisted in many cases by a marking-off table. This is a flat cast-iron slab about 4 x 6 feet surface which is ribbed underne...
-246. Varieties Of Patterns
In forms of construction, patterns may be divided into three varieties, viz., (1) solid patterns, (2) hollow and skeleton patterns, and (3) sweeps. Small patterns are built solid, made up in most c...
-247. Skeleton Patterns
The skeleton pattern is well adapted to irregular hollow castings, such as the steam nozzle with three outlets, a drawing of which is shown in Fig. 115. The pattern is made in two parts divided along ...
-248. Sweeps
When the surface of a casting, such as a steam cylinder, a propeller blade and hub, etc., is wholly or in its main features a surface of revolution, or may be generated by the revolution of a line abo...
-Chapter IX. The Foundry. 249. The Work Of The Foundry
The work of this shop is divided principally between moulding and casting. Moulds are prepared by aid of patterns sent from the pattern shop, and are filled with molten metal which solidifies to the m...
-250. Iron, Brass And Steel Foundries
The methods used in iron and brass foundries are closely associated, and these two branches are usually under one shop superintendent and in adjacent buildings. The steel foundry is separate, as its m...
-251. Classes Of Moulds
There are four general classes of moulds, designated as follows: (1) Open sand moulds. (2) Green sand moulds. (3) Dry sand moulds. (4) Loam moulds. Open sand moulds are the cheapest cla...
-252. Example Of An Open Sand Mould
Fig. 117 shows an open sand mould in course of preparation. This is very simple and demands no particular skill. Two boards, A and B, are imbedded on edge in the foundry floor and are leveled along th...
-253. Example Of A Green Sand Mould
Fig. 118 shows a typical small green sand mould in a two-part flask. This is a mould of the pattern shown in Fig. 108. The upper half of the mould is the cope and the lower half is the drag or nowell....
-254. Essential Features Of A Mould
All moulds, whether for steel, iron or brass, must fulfill the following general requirements, viz.: (1) They must be made so that the pattern can be removed readily therefrom. (2) Not only must...
-255. Foundry Equipment
The main equipment of the foundry may be stated as follows: (1) Moulding sands in bins, and other moulding materials. (2) Flasks in which moulds are made. (3) Moulders' tools and accessories ...
-256. Moulding Sand
This is the most important of the moulding materials. In different forms, it has different uses and is given different names, such as green sand, loam, facing sand, core sand, brass sand. All moulding...
-257. Other Materials Used In Moulding
Designating moulding sand as first on the list, other important moulding materials are named as follows: (2) Fire clay is a pure clay (oxide of aluminum) much used when mixed with water as a plasti...
-258. Flasks For Green And Dry Sand Moulds
Moulds of these two classes are made in flasks of various shapes and sizes. Wood or iron flasks are used for green sand molds and cast-iron flasks are used for dry sand and steel moulds. Fig. 120 s...
-259. Tools Used In Moulding
The moulder's tool kit is simple and includes articles of the following list, most of which are shown in Fig. 122: (1) Vent wire for sticking vent holes through the sand of the mould. (2) Patter...
-260. Example Of Making A Small Mould
The work of making a mould of the pattern in Fig. 108 is here given briefly to show the essential steps in sequence. This is applicable in general to green sand and dry sand work. The completed mould ...
-261. Moulding Machines
These machines are profitably employed in foundries which make a great number of small duplicate castings. They are designed and built to repeat certain motions and operations which occur in the work ...
-262. Cores
Cores are more or less surrounded by molten metal and are therefore subjected to more concentrated heat than other parts of the mould. To serve their purposes they must be made especially (1) to resis...
-263. Chaplets
There are many cases in moulding in which a core is not adequately supported by its bearings in the sand of the mould, particularly if it has but one bearing or is not a straight core. It is the pr...
-264. Chill Moulds
Surfaces of cast-iron castings subjected to constant wear, such as car-wheel rims, anvil faces, and vehicle wheel boxes, are chilled to render them hard and tough. The chilling is done by sudden cooli...
-265. Example Of A Loam Mould
Fig. 127 shows a cross-section of a loam mould, with the parts assembled and bound together firmly. It is now ready to be lowered into a pit dug in the foundry floor and surrounded by sand packed insi...
-266. Building A Loam Mould
Each of the detachable parts of a loam mould is so built on its own plate that it can be handled separately from the other parts. The mould is begun by leveling the heavy foundation plate B (Fig. 1...
-267. The Cupola
Pig and scrap iron for castings are generally melted in a cupola, although a reverberatory furnace may be used. Fig. 133 shows a typical cupola in cross-section. A cast-iron or cast-steel base ring B ...
-268. Operation Of The Cupola
A cycle of service for a cupola in active use is usually repeated each 24 hours. Briefly the operation throughout the 24 hours is as follows: A day's melting having been finished, and the blower stopp...
-269. Ladles
Iron is received in ladles from the cupola and is poured from these into moulds. Ladles are made of rolled steel plate and plastered inside with a wet mixture of silica sand and fire clay. Large ladle...
-270. Foundry Iron
Although foundry iron is now selected by its composition as shown by chemical analysis, yet the designations of white, mottled, and grey irons, are still used to classify pig iron according to the car...
-271. Brass Furnaces
The materials and methods used in making iron and brass moulds are practically the same, although the means of melting these metals for castings are different because brass melts at a lower temperatur...
-272. Defects In Castings
The following defects and their causes are well known to foundry men: (1) Surface and interior cavities are caused by too little metal, or by runners and risers too small to remain liquid and feed ...
-273. Remedies For Defective Castings
In some cases defective castings may be remedied. (1) Strains are removed from castings by annealing. This is usually necessary only with steel castings, or chilled cast-iron castings. (2) A war...
-274. Steel Castings
In strength and other qualities steel castings resemble steel forgings much more than they do cast-iron castings. But for their marked superiority over cast-iron castings doubtless their greater cost ...
-275. Steel And Iron Foundries Compared
Although the work of making steel castings is closely associated with the steps in making cast-iron castings, yet there are several requirements of great importance in the preparation of steel moulds ...
-276. Moulds For Steel Castings
Dry sand moulds made in iron flasks are used for steel castings, although small steel castings are frequently made in green sand moulds contained in wood flasks. The boundry between the use of green a...
-277. Particular Requirements Of Steel Moulds
The higher heat of steel when cast requires that (1) particular attention be paid to the venting of moulds, and that (2) the mould surfaces be especially treated to prevent washing away, or scabbing,...
-278. Surfaces Of Steel Moulds
After the pattern has been removed from a steel mould, the face of the mould and particularly any sand projections subject to the wash of the metal, are stuck with wire nails more or less close togeth...
-279. Means Of Avoiding Shrinkage Cracks
Shrinkage cracks may occur where thin and thick parts of a casting join, due to the unequal rate of cooling of the different masses of metal. These are prevented by making changes of thickness very gr...
-280. Avoiding Surface Or Interior Cavities
The great shrinkage of steel would cause surface or interior cavities in the casting were it not fed by its runners, risers, and feeding heads. The static pressure of the metal in these insures the fi...
-281. Steel For Castings
In steel works, where steel is made, castings are poured from open-hearth, Bessemer, or crucible steel, as may be required. The making of steel castings in large steel works is usually an incidential ...
-282. The Tropenas Converter
The product of this converter is acid steel produced as in the Bessemer process except that the Tropenas converter directs its blast against the surface and not through the metal. Fig. 137 shows a Tro...
-283. Temperature Of Steel For Pouring
The temperature of steel when poured into moulds is highly important, and varies with the size of the casting. An experienced foundry superintendent judges the right pouring temperature by simple insp...
-284. Annealing Steel Castings
Because of the considerable change in form by contraction during cooling, steel castings of large bulk and particularly varying thickness, are apt to be under stress due to the contraction of a heavie...
-285. Defects In Steel Castings
Steel castings are subject in general to the same defects named for cast-iron castings, but particularly does the manufacturer of steel castings have to be continually on guard against three classes o...
-Chapter X. The Blacksmith Shop. 286. The Blacksmith And Forge Shop
The work of shaping iron into many forms by heating and hammering is a process which has been long in vogue, and it is far more widely known and practiced to-day than any of the other metal-shaping pr...
-287. Materials For Forgings
The stock for working into small forgings comes from the rolling mill as rods and bars of various sections. This material, at the present day, is principally mild steel, this having displaced most of ...
-288. Shop Equipment For Hand Forging
This equipment consists of (1) a suitable forge for heating, (2) an anvil mounted solidly at a convenient working height, (3) hammers in form and weight suitable for shaping forgings to best advantage...
-289. The Forge
Forges are of various forms, portable and stationary, and framed of brick or iron. Most of them use coal for fuel, but brick-lined furnaces for oil or gas fuel are now in common use. For coal-burning ...
-290. The Anvil
Fig. 138 shows an anvil of usual form. The body and horn are made of wrought iron or forged mild steel, with a 3/8-inch face of crucible tool steel welded on the body. However, some anvils are made by...
-291. Smiths' Hammers
These are made of a medium-carbon crucible cast steel. They must be hard though not brittle. Hand hammers weigh about two pounds, and sledge hammers weigh from 5 to 20 pounds, though for ordinary work...
-292. Tongs And Anvil Tools
Fig. 141 shows three varieties of tongs much used in blacksmithing, though there are many special forms for holding peculiarly shaped forgings. Fig. 142 shows tools used in anvil work. They are des...
-293. Fuel For Use In Forges
Up to recent years soft coal was the most extensively used fuel for forges, but petroleum residue is now much used, and natural gas is used in localities which supply it. Soft coal is used because ...
-294. Heating In A Forge
A clean fire of incandescent coal all around a piece to be forged will insure even heating. There must be a substantial layer of burning coal between the forging and the tuyere, else the oxygen of the...
-295. Terms Commonly Used In Forging
Among the terms used may be mentioned the following: (1) Upsetting is the increase in thickness and decrease in length produced by hammering a hot piece of metal on the end. Upsetting is resorted t...
-296. Measuring Stock For Forging
Fig. 144 shows two dimensioned sketches such as would be given a blacksmith for making an angle and a ring. To cut stock to the exact length for the angle, take the length of the neutral axis ah, whic...
-297. Welding
This process of joining together two pieces of iron has long been practiced in blacksmithing, but is now by no means confined to the blacksmith shop nor to the metal used therein. Fig. 144. ...
-298. Hardening And Tempering At The Forge
The forging, hardening and tempering of steel tools for cutting metals have long been practiced as a part of blacksmithing. The process used by blacksmiths to give an edged tool the correct degree of ...
-299. Color Table For Judging Hardness
The first color observed after rubbing a bright spot on a piece of quenched steel is a light straw, denoting the greatest degree of hardness possible for that particular piece of steel. As the heat tr...
-300. Hardening Of Alloy-Steel Tools
The alloy steels are so various in composition that no general rule can be given for their hardening. The best method is to follow the directions given by the maker of each grade of this steel, and no...
-301. Influence Of The Cooling Medium In Hardening
The practice of using water, brine, oil and other liquids for quenching a steel tool after heating for hardening, varies with different blacksmiths. As was previously mentioned, two of the factors con...
-302. Annealing In The Blacksmith Shop
Occasionally it is necessary to take the temper from a piece of tool steel for forging into another shape, i. e., the steel is to be softened. It is heated to a red heat and is placed betwe...
-303. Equipment Of The Forge Shop
As this part of the blacksmith shop is intended for heavy work its principal equipment is one or more steam hammers of the small single frame type or of the heavy double frame type. Other essential eq...
-304. The Steam Hammer
Steam hammers are single acting when the hammer is raised by steam and falls by gravity alone; or are double acting when the hammer is raised and forced down by steam. The smaller hammers have sing...
-305. Appliances Used With The Steam Hammer
Blooms and large billets are held during forging by a chuck and porter bar, or by a porter bar clamped to one end of the forging. Smaller billets are gripped by heavy tongs made to conform to the size...
-306. Heating Furnaces
The open forge is not well adapted to steam-hammer work, but some form of closed furnace is necessary to give the required amount of concentrated heat. Oil, gas or coal furnaces are much used, with pr...
-307. Notes On Steam-Hammer Forging
(1) Upsetting in large forge work may be done by holding the heated billet between the hammer and the anvil dies and bumping it with a battering ram known as a tup or monkey. This is a heavy mass ...
-Chapter XI. The Machine Shop. 308. Scope Of Machine-Shop Work
The machine shop is equipped for the work of finishing castings and forgings to exact form and dimensions. This work is done principally by means of machine tools which cut off superfluous metal, and ...
-309. Machine-Shop Practice
The time required for work of such accuracy as is done in the machine shop, and the high cost of skilled labor for efficient work makes machine shop processes very expensive - often excessively so. Mo...
-310. Machine-Shop Equipment
The equipment of a machine shop naturally depends upon the size and variety of work it has to do. There are different sizes of machines of the same kind for machining different sizes of castings and f...
-311. Marking Work To Be Machined
An important preliminary in a machine shop is the lying off and marking of work. Forgings, castings and other work to be machined must be marked to indicate the location of holes to be drilled, the ax...
-312. The Marking-Off Table
To afford means for marking work accurately preparatory to machining it, a marking-off table is provided. Certain measuring and marking tools, and suitable blocks for supporting the piece to be marked...
-313. Tools And Appliances For The Marking-Off Table
To support a piece of work so that its chosen plane of reference may be parallel or perpendicular to the top of the table, a number of chocks and bars are used. Fig. 154 shows specimens of chocks C an...
-314. Refined Measuring In Machine Work
The machine shop is the shop on which devolves the requirement of finishing work to specified dimensions within very small limits of allowable error. The discerning of small differences in physical...
-315. Tools For Measuring
The steel rule is the simplest form of measuring tool used in the machine shop. It cannot be used, however, for measuring lengths smaller than can readily be discerned by the eye. For such measurement...
-316. The Micrometer Caliper
This instrument, a type of which is shown in Fig. 170, is used for measuring thicknesses and external diameters. It is the instrument of the greatest degree of precision used in machine-shop measuring...
-317. Machine Tools
A list of machine tools for a well-equipped shop is as follows: (1) Lathe. (2) Drilling machine, commonly called a drill. (3) Planer. (4) Shaping machine or shaper. (5) Milling machine....
-318. The Lathe
In this machine, as in the wood lathe, work revolves about a fixed axis between the centers and the cutting tool moves either (1) parallel to the axis, cutting a cylindrical or spiral surface; (2) per...
-319. Varieties Of The Lathe
Lathes are designated according to their different types. Among these are (1) hand lathes; (2) machine lathes; (3) gap lathes, and (4) turret lathes. The hand lathe was mentioned with the machinery...
-320. Lathe Tools
Fig. 174 shows the different shapes of tools ordinarily used in lathe work. These are made of high-carbon steel, or preferably of self-hardening alloy steel for heavy work. The cutting ends are forged...
-321. Lathe Attachments
Several attachments are provided to enable a lathe to be used for various kinds of work. The most important among these are the face plate, chuck, mandrel, boring bar and steady rest. There are other ...
-322. The Lathe Chuck
Oftentimes work can neither be suspended between centers nor bolted to the face plate. In this case it is held by a chuck, a type of which is shown in Fig. 176. The four jaws (one of which is marked B...
-323. Lathe Mandrels
There are many pieces of lathe work which are pierced with a cylindrical hole and which can be mounted on a bar suspended between lathe centers. Fig. 177 shows an arrangement of this kind. The bar B i...
-324. The Boring Bar
For boring out hollow cylindrical work on the lathe, it is usually secured to the face plate as shown in Fig. 179. If the work does not extend more than 6 or 8 inches from the face plate, it may be...
-325. The Steady Rest
When a long piece of work is suspended between lathe centers it will sag more or less. Also very heavy work is too heavy for safe support by the lathe centers and additional support must be provided. ...
-326. Centering Work For The Lathe
Lathe centers must be accurately pointed to an angle of G0. They must be kept sharp-pointed, smooth, and absolutely free from grit or metal chips. A bar to be suspended in the lathe must be ce...
-327. Cutting Of Screw Threads
A screw thread is a helical groove cut on an internal or an external cylindrical surface. The cutting of threads is best and cheapest done by machine. Bolts and nuts are usually cut by dies and taps h...
-328. Forms Of Threads. Definitions
A screw thread may be conceived as formed on a cylinder by winding thereon a piece of triangular wire, as shown in Fig. 183. N is a nut, threaded inside to turn on the screw. If the wire is wound a...
-329. Standard Threads
The unlimited forms of threads which may be used has brought about efforts to standardize the form and pitch of the V thread. The efforts have resulted in the U. S. C=860 pitch Fig. 185. ...
-330. Drilling Machines
The cutting of cylindrical holes of greater or less size in metals is a very varied requirement in machine-shop practice and many methods are employed for accomplishing this work, depending upon the d...
-331. The Vertical Drill
Fig. 188 shows a vertical drilling machine of a type much used. The drill is carried in a socket in the lower end of the vertical spindle VV. The spindle is made to revolve by a belt on the cones CC, ...
-332. The Radial Drill
The changing of position of work on a machine consumes time which may add considerably to the expense of large work. The radial drill is so designed that when a piece of work is secured to the drill t...
-333. Drills And Attachments For Drilling Machines
Fig. 190 shows three twist drills and a countersink which are much used with drilling machines. Drill C is made of a twisted bar of highspeed steel. Drills A and C have taper shanks. They are placed i...
-334. The Planer
This machine is used to cut plane surfaces or straight grooves. Fig. 192 shows a type of planer much used. Work is secured usually by bolts and clips to the heavy table T, the surface of which is leve...
-335. Types Of The Planer
For very heavy work of considerable bulk, an open-sided planer is used. This is somewhat similar to the planer just described, except that one of the housings is omitted. Another type of planer des...
-336. Planer Tools
As in the case of lathe tools, these are made of rectangular steel bar material, forged, hardened, and ground to shape. The planer has fewer regular tools than the lathe. There is no threading tool fo...
-337. The Planer Chuck And Planer Jack
The chuck or vise shown in Fig. 193 is very useful for planer and shaper work. It is bolted to the table and used to hold small work in exact position for accurate cutting. Fig. 193. - Planer...
-338. The Planing Of Propeller Blades
The driving surface of a propeller blade is made up of straight line elements radiating from the axis of the propeller. This fact enables a true and smooth surface to be machined on the blade by means...
-339. The Shaper
This is virtually a planer for planing small work. It is not designed like the planer, however, and the essential difference is that the work table remains stationary, except for the feeding motion, a...
-340. The Milling Machine
This machine is shown in simple form in Fig. 19G. Milling machines are used for both plain and intricate cutting of great variety. They are adopted to that kind of cutting which is of particular or pe...
-341. Description Of The Milling Machine
Work is held in a vise or other attachment which is bolted to the slots of the table (Fig. 196). Wheel-shaped cutters placed on the arbor are made to revolve by means of the main spindle which is holl...
-342. The Universal Milling Machine
The machine in Fig. 196 is known as a plain milling machine because its table cannot turn on the saddle. The machine in Fig. 197 is a universal milling machine, as its saddle is made in two parts, div...
-343. Milling-Machine Cutters And Arbors
Fig. 199 shows a group of cutters, arbors and collets. Cutters are made of high-speed steel for roughing cuts and of carbon steel for lighter or finishing cuts. After a cutter is hardened for cutti...
-344. Milling-Machine Attachments
The usual milling-machine attachments are the vise and the dividing head, both for holding work. Fig. 199. - Milling-Machine Cutters, Arbors and Collets. There are, beside these, a number ...
-345. The Boring Machine
There are two general types of this machine, both of which were designed primarily for boring hollow cylinders too large for boring on the lathe. The two types of the boring machine, each of which has...
-346. The Horizontal Boring And Drilling Machine
Fig. 200 shows a representative type of this machine. A cylinder to be bored is so clamped on the upper cross-table T, and the table is so adjusted, that the cylinder axis and that of the spindle SS a...
-347. The Vertical Boring And Turning Mill
This machine, shown in Fig. 201, is used for boring large steam cylinders, gun-hoop forgings, locomotive drive-wheel tires, fly wheels, and similar large work. This work may also be faced or turned on...
-348. The Slotting Machine
A type of this machine is shown in Fig. 202. This is known as the crank-driven type to distinguish it from the heavier gear-driven type. The slotting-machine movements resemble very much those of t...
-349. Tools For The Slotting Machine
Fig. 203 shows a few slotting-machine tools for general use, although many forms may be made for special uses. They are designated as follows: (1-2) Roughing tools. (3) Finishing and filleting t...
-350. Pipe Cutting And Threading Machines
The cutting and threading of steam and gas pipes is done to a considerable extent by hand appliances, but the best results are obtained by a machine which cuts and threads a pipe while holding it rigi...
-351. Tool-Sharpening Machines
The grindstone is still employed for sharpening metal-cutting tools, but it has been in a great measure displaced by emery or carborundum grinding wheels. Many types of tool-grinding machines are n...
-352. Metal-Cutting Saws
It is frequently necessary to cut bars, rods, standard rolled shapes, etc., into definite lengths for various needs. This may be done by shearing or by sawing, and the oxy-acetylene flame is now used ...
-353. Forcing Presses
These are used for forcing wheels on spindles or shafts. They vary in size from those requiring hand power applied through screw rods, to those requiring the pressure of a heavy hydraulic cylinder. A ...
-354. Machine-Shop Notes
Under this paragraph will be given a few notes applying to machine-shop practice in general. (1) The cutting speed of tools is determined by the heat generated in cutting. When the tool and the wor...
-355. Bench Work In The Machine Shop
Some work in the machine shop, as chipping, filing, scraping and reaming, is done by hand. Cutting threads on small bolts and pipes is frequently done at the bench, although such work is not economica...
-356. Cold Chisels
These are usually made from octagon-bar steel, hardened at the cutting ends. The two forms most used are the flat chisel A, and the cape chisel B, shown in Fig. 206. The blade of B is much narrower th...
-357. Files
The many kinds of files are classed according to (1) length; (2) form of teeth, and (3) shape of cross section of the body of the file. The usual forms of teeth are classified as shown in Fig. 207....
-358. Taps And Dies
Thread cutting is more accurately and economically done by machine, but necessity frequently arises for cutting threads by hand. Taps and dies for hand work are made in many forms and sizes, of variou...
-359. Wrenches
Hand wrenches for tightening or loosening nuts are of several forms, some of which are shown in Fig. 212. The wrenches shown are designated as follows: (1) Monkey wrench (adjustable). (2) Pocket...
-360. Scrapers
To bring perfect contact between two metal surfaces, each is coated with a fine film of red lead and oil, and the surfaces are then rubbed together. Upon separating them, the high spots may be plainly...
-361. Surface Plates
For testing the accuracy of a surface which must be exactly plane, one of the surface plates, shown in Fig. 214, is used. These plates are sold in pairs so that one may be a test of accuracy of the...
-362. Abrasive Materials
These are used for polishing metal surfaces by grinding away the marks left by the file or by machine-cutting tools. They are frequently seen in the forms known as emery, carborundum, and crocus cloth...
-363. Portable Tools
There is frequent necessity for drilling and other cutting on work which cannot be moved to a machine. There have been devised many types of small portable machines, usually designated as portable too...
-364. Pipe Fitting
This is the term used to designate the work of putting together various lengths of piping and their connecting parts. This work is associated with the machine shop, where the required lengths of pipin...
-365. Fittings
Fig. 216 is a specimen of pipe-fitting work made up to show the use of various types of fittings. The kind, size, and style of each fitting is given in the preceding list. Fittings are usually made...
-366. Tools Used In Pipe Fitting
The hand tools ordinarily used in pipe work are shown in Fig. 217. The pipe vise holds pipe for cutting, threading and fitting parts together. The tongs and wrenches grip the pipe for holding or turni...
-367. Bolts, Nuts And Machine Screws
These articles are products of the re-manufacture of metals. Those for general use are made according to adopted standards of shape and size. A machine screw is a small bolt with a slot in the head...
-Chapter XII. The Boiler Shop. 368. Work Of The Boiler Shop
The work of building a boiler is partly that of shaping flat steel plates into cylindrical and flanged forms, and partly that of assembling with these forms certain products of other shops, as tubes, ...
-369. Types Of Boilers. Their Manufacture
The many types of boilers may be classed under two general divisions, viz.: (1) Shell or fire-tube boilers. (2) Pipe or water-tube boilers. The shell boiler is made in several forms, of which...
-370. Boiler Material
The material used for plates, rivets, braces, and all other parts on which the structural strength of a high-grade boiler depends are made of a low-carbon open-hearth steel in which is allowable only ...
-371. Preliminary Diagram For Laying Out Work
The dimensions and all details of a boiler to be built must be shown on suitable drawings for the guidance of the master boilermaker in laying out and directing the work of building the boiler. Suppos...
-372. Diagram For Laying Out Shell Plates
The shell is developed on a flat surface, the position of each plate joint is marked with reference to the top, bottom, and side center lines, which are the first lines placed on this diagram, and the...
-373. Preparation Of Plates For Laying Out
Boiler plates are ordered from the rolling mill as flat plates. Their dimensions are determined from the drawing of the boiler, and the plates ordered should be near their finished dimensions, leaving...
-374. Operations For Shaping Plates
The operations for shaping boiler plates are as follows: (1) Planing plate edges. (2) Rolling plates to cylindrical form. (3) Flanging. (4) Drilling holes for rivets, stay bolts, tubes, et...
-375. Planing Plate Edges
Edges of shell plates are planed to the finished dimensions before the plates are rolled. When the boiler head is made up of more than one plate, the straight edges of these plates are planed, but the...
-376. Plate-Bending Rolls
This name is given to the machine shown in Fig. 224 to distinguish it from the plate straightening rolls. The machine consists of three solid-forged rolls supported parallel in heavy bearings. The low...
-377. Marking A Flange
In boiler making and in sheet-metal work generally, a flange is a margin of metal along the edge of a plate turned at a greater or less angle out of the plane of the plate. Fig. 226 shows a cross s...
-378. Methods Of Flanging
Flanges may be turned (1) by beating down the plate edge with hand mauls, while the plate is suitably held on a former or between two heavy bars, or (2) by the hydraulic flanging machine. Plates are u...
-379. Equipment for Flanging by Hand
Fig. 228 shows a flanging clamp for holding plates for straight flanging. Angle bars of various curvatures over their angles are furnished for placing over the lower clamp to give the desired curvatur...
-380. The Hydraulic Flanging Press
This machine is shown in Fig. 230. It consists of a heavy cast-iron body carrying four hydraulic cylinders, and a suitable table on which work is held steady while being flanged. The plunger head o...
-381. The Hydraulic Accumulator
The great pressures used in hydraulic machines are supplied from intensifiers on the principle of that shown with the forging press in a previous chapter, or from accumulators. Water in an accumulator...
-382. Flange-Heating Furnace
Fig. 233 shows a hearth or furnace, partly in cross section, for heating the edge of a plate for flanging. It is a brick-walled basin re-inforced around the sides with iron plates and covered with per...
-383. Straightening And Annealing Of Flanged Plates
The work of flanging usually warps a plate more or less, though the work of straightening can frequently be done before it goes to the annealing furnace. Flanged plates are placed in a large coal or o...
-384. Drilling Holes In Boiler Plates
Rivet and other holes in boiler plates must be drilled and not punched. Holes must be carefully located on the plates from the layout diagrams. Plates which are not to be heated for flanging or other ...
-385. Assembling The Parts Of A Boiler
After the plates composing a boiler have been trimmed to finished dimensions, rolled to the required curvatures, flanged, and have had enough rivet and other holes drilled for bolting them together te...
-386. Riveting
Riveting is done by (1) hydraulic riveting machines, both stationary and portable; by (2) portable pneumatic riveters, and by (3) hand hammers. Portable hydraulic riveters are massive and must be carr...
-387. Rivet-Heating Furnace
Rivets are heated preparatory for driving in a forge, or more efficiently in a small oil-burning furnace, a type of which is shown in Fig. 236. This consists of a small sheet-steel box, lined with fir...
-388. Methods Of Holding Boiler Tubes In Place
Fig. 237 shows the method of holding tubes in a shell boiler. The ends of an ordinary tube are expanded to fit tightly against the sides of the holes in the tube sheets. The stay tubes, heavier than o...
-389. Chipping And Caulking
After the riveting of a boiler is completed, the various lapped seams are made tight by caulking the beveled edges of the sheets. A flanged joint is usually made, as shown in Fig. 240, with the lap of...
-390. Corrugated Furnaces
The locomotive type of boiler has a square fire box at one end, but the cylindrical type of marine-shell boiler is fitted with one or more corrugated furnaces such as is shown in Fig. 221. These furna...
-391. Other Equipment For The Boiler Shop
Besides the equipment so far named for this shop, the shop should have (1) Power shears for shearing heavy steel plates up to about 1 1/2 inches thick. (2) Power punch for punching holes in plat...
-392. Power Shears And Punch
One type of these machines is shown in Figs. 241 and 242. Plates are held flat for shearing or punching in chain slings carried on the hook of the crane. Two men usually hold the plate to guide it und...
-393. Hand Shears And Punch
Fig. 243 shows a convenient form of this machine. It may be bolted to a heavy bench or set on a portable stand. Small punches are frequently fitted to be operated by hydraulic pressure. ...
-394. Shapes Of Rivets
Fig. 244 shows the usual shapes of rivets for ship, bridge, boiler and tank work. They are designated as follows: Fig. 244. - Types of Rivel Heads. (1) Pan head. (2) B...
-Chapter XIII. Other Shops - Special Processes. 395. Sheet Metal Work
This is a subsidiary work in large building plants. It consists of making tanks, casings, large copper pipes, fenders, wheel guards, smoke and other conduits, and receptacles for oils and other materi...
-396. The Copper Shop. Materials Used
There is usually considerable copper-pipe work to be done in a ship or engine-building plant. This is the principal work of the copper shop. Copper is much used for small and medium-sized steam pip...
-397. Copper Shop Equipment
This shop is equipped with various hand appliances for cutting, bending, hammering and riveting tubes and sheet metals; with small furnaces for brazing and annealing; and with apparatus for soldering....
-398. Cutting, Bending And Riveting Tools
The principal tools for these uses are as follows: (1) Bench shears. These are used for heavier cutting and are supported while in use by placing the bend of the lower handle in a square hole in th...
-399. Coppersmith Hammers
Fig. 252 shows the hammers made especially for coppersmiths' use. Their designations and uses are as follows: (1) Raising hammer. Used to cup flat work. (2) Planishing hammer. This has polished ...
-400. Brazing
This is a process much used for uniting copper, brass or iron in a solid metallic joint of considerable strength, though the strength of the joint is not equal to that of the solid metal. The brazing ...
-401. Heat For Brazing
The necessary heat for brazing is usually supplied by a flat-topped forge or brazing table such as is shown in Fig. 253. This forge uses gas or oil fuel forced into the flame by compressed air. The ai...
-402. Annealing
Copper and brass sheets are frequently shaped by hammering cold, as in shaping a hemispherical or other concave receptacle from a flat sheet, or in making bent copper pipes. The metal becomes more or ...
-403. Soldering
This process of joining metals is much used by tinners and other sheet-metal workers for joints requiring but moderate strength. It is a simpler and more convenient process then brazing, as solder mel...
-404. Method Of Soldering
Two pieces of metal to be soldered together must be filed or scraped to a clean metallic surface if not already bright. They are brought into the position in which they are to be soldered and firmly h...
-405. Copper Pipe
This pipe is often made by the coppersmith from sheet copper, but it is better and cheaper to use lengths of seamless drawn pipe from the tube mill. The mill supplies pipe up to 8 inches, or possibly ...
-406. Joining Lengths Of Copper Pipe
One length of pipe may be joined to another by composition flanges as shown in Fig. 255 or in a permanently brazed cup joint as shown in Fig. 256. The flange joint may be readily taken apart by rem...
-407. Brazing A Branch In A Copper Pipe
To connect a branch to a length of pipe B, Fig. 257, drill a hole about 3/8-inch in diameter in the pipe. Beginning with the small collar lifter, lift the edges of the hole carefully and evenly all ar...
-408. The Plate And Angle Shop
Plates and structural shapes of mild steel used in ship building are cut and bent to shape in this shop, the principal equipment of which consists of.: (1) Power punches, used principally for punch...
-409. The Bending Slab
Fig. 258 shows a level floor of heavy cast-iron slabs used for bending angles and other structural shapes to various curved forms for ship frames. The slabs are well supported on permanent foundations...
-410. Special Processes
A few special processes are outlined in the paragraphs which follow. These are selected because of the importance of their products or because of the application of the processes themselves to many di...
-411. Malleableizing
This is the process of rendering cast-iron castings malleable, or capable of bending without breaking. Castings are not only relieved of brittleness, but a considerable degree of toughness and ductili...
-412. Case Hardening
This process is the reverse of malleableizing, i. e., it adds carbon to forgings of wrought iron or mild steel to make them hard for resisting wear. Many articles, such as set screws, bolts and nuts, ...
-413. Pipe Bending
Mention has been made in another paragraph of methods of bending copper pipes and small iron or brass pipes. Two essentials in pipe bending are (1) to keep the pipe from flattening into elliptical ...
-414. Joining Metals
There are now in use many important means of uniting metals solidly together. These have many applications in manufacturing and one or more of them may frequently be availed of in making permanent rep...
-415. Electric Welding
When an electric current encounters resistance in its circuit a portion of its energy is converted into heat. If an electric current flows across the junction of two rods placed in mutual contact, mor...
-416. The Resistance System
This system, developed by Prof. Elihu Thompson, is much used to weld together wires, rods, small forgings and other parts which are made separately for quick production. It is used in welding links of...
-417. The Arc System
This system is used in repairing iron castings in a way which resembles soldering. A crack or cavity is filled up with drops of cast iron or cast steel which melt from a rod as shown in Fig. 262. This...
-418. The Thermit Process
The essential feature of this process consists of generating, by chemical union between oxygen and aluminum, an intense local heat which produces from the reaction a certain amount of molten iron. Thi...
-419. Making A Thermit Weld
The simplicity of the equipment for thermit welding or casting makes it particularly valuable for work far removed from shop facilities. A quantity of thermit is placed in a conical, covered crucible ...
-420. Blow Pipe Welding
The flame of a combustible gas may be so regulated in its shape and intensity by a properly constructed burner that it can be effectively used for local heating such as is needed in welding. In the co...
-421. Method Of Making A Blow Pipe Weld
The ease with which an oxy-acetylene or an oxy-hydrogen outfit may be set up where needed, and the small size of the blow pipe and its flexible rubber-hose connections, make such an outfit very practi...
-422. Application Of Blow-Pipe Welding
This method is much used to join the edges of wrought iron or steel plates up to an inch or more in thickness. Heavy plates conduct away the heat so rapidly that it may not be possible for the burner ...
-423. Blow-Pipe Cutting Of Metals
A remarkable method of cutting metals has been developed in the use of the oxy-hydrogen and oxy-acetylene burners. To a blow pipe used for heating is attached an additional tube through which a jet...
-424. Burning On
This is a method employed for mending a cracked, broken, or honey-combed casting of cast-iron or brass. Many costly castings which would otherwise have to be discarded may be made sound by this proces...
-425. Puddling
This is a method of repairing small broken castings similar to burning on. A mould of clay or plaster of Paris is formed about the broken parts of a small casting as shown at o, Fig. 267. - U...
-426. Classification Of Welding Methods
Those methods which accomplish the union of two pieces of metal directly by fusion of one to the other, without the intervention of another metal at the joint, are classed as autogenous methods. Those...
-427. Grinding
The popular idea of grinding is its use in shaping more or less roughly the edges of cutting tools and in removing fins and other small projections from forgings and castings as a step toward making t...
-428. Grinding Machines
Machines for accurate grinding are usually built on the general lines of either a lathe or a milling machine. In these machines, the grinding wheel takes the place of the cutting tool, and it is so mo...
-429. Grinding Wheels
Experience has shown that the kind of wheel, its periphery speed, the extent of contact between the wheel and the work, and the rate of feed of the wheel over the work are essential factors in success...
-430. Lapping
This is a method of grinding external and internal cylindrical surfaces to a finer degree of accuracy (1/10000 inch) than can be obtained with certainty in the use of a grinding wheel. It is under mor...
-431. Armor-Plate Making
An armor plate should be hard enough on the outer surface to prevent penetration by a shell and tough enough under the hard surface to resist breaking or cracking. Armor plate is commonly made of nick...
-Appendix. 432. Table Of Brasses And Bronzes
The following table gives a list of the brasses and bronzes in common use. Their compositions as here given are more or less varied by manufacturers. The skill of melters, and their personal experi...
-433. Degrees Of Hardness Of Steel Tools
The amount of carbon in various well-known tools and implements made of hardened steel is shown approximately by the following list: .6 to .7 per cent. .7 to .8 per cent. ...
-434. File Making
To illustrate many of the essential operations in making tools, a description of file making is here given. This description applies to a flat tapered file of rectangular cross section. The steel used...
-435. Wire Gage Table
The following table is given to show a comparison of the various wire gage systems: Actual Dimensions in Fractions of an Inch. Wire Gage Units. 1 ...
-436. Wire Dies
Wire dies are usually made of chilled white cast iron, hard-carbon steel, and alloy steel. The very smallest sizes of dies are made of diamonds because drawing soon enlarges a very small hole in a ste...
-437. Dimensions Of Standard Iron Pipes
The following table shows the standard dimensions of iron pipe, including standard threads for ends of the pipe. These standard sizes are made in wrought iron, mild steel, and brass as commercial prod...
-438. Methods Of Threading Bolts
Bolts are usually threaded by being held firmly in a machine which runs a briskly revolving threading die along the body of the bolt as far as the thread is to extend. These dies are kept deluged with...
-439. Illustration Of Automatic Screw Machine Work
Fig. 270 shows the steps in the work of cutting the small helical gear wheel shown at W in Fig. 92, Chap. VI. This is done in six operations, requiring a total of 80 seconds of time. A dimension drawi...
-440. Shop Location And Equipment
In locating and equipping a manufacturing plant the following-named factors are of importance: (1) The cost of obtaining raw materials at their source of supply, their quality and the available qua...
-441. Allowance For Forcing And Shrinkage Fits
A table is here given, showing the usual allowance or difference, in fractions of an inch, between a shaft and the hole in which it fits, for forcing and shrinkage fits. Shrinkage fits....
-442. U. S. Standard Screw Threads
Diameter of screw. Threadsper inch. Diameter at root of thread. Diameter of screw. Threadsper inch. Diameter at root of thread. ...
-443. Hydraulic Data. Table Of Gallons
Cu. ins. in a gallon. Wt. of gal., pounds avoirdupois. Gallons in a cu. ft. One cu. ft. of water at its maximum density. 39.1 Fahr., weighs 62...









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