Appendix III. Useful Tables

Description

This section is from the book "Carpentry", by Ira Samuel Griffith. Also available from Amazon: Carpentry.

Appendix III. Useful Tables

Fractional Equivalents For Decimal Values

Where rafter lengths are determined by multiplying unit lengths by the run, the answer will almost invariably result in a decimal. Such decimal values may be readily translated into fractional forms by means of the accompanying table.

Example: A roof of ⅓ pitch has a common rafter run of 14'; find the length of common rafter.

Answer: 14x14.42"=201.88" or 16.82'. By the table, .82 = 53/64. A carpenter, however, would not care for such accuracy; the nearest 1/16" or even ⅓" would be sufficient.

Wood And Machine Screw Sizes

The difference between consecutive sizes is .01316".

Frequently the carpenter wishes to know the diameter of hole necessary to receive the shank of a screw of a certain gage. Should a screw gage be accessible, he may readily determine this. Should no gage be at hand, he may determine the size of hole by consult-ing the accompanying table of Wood and Machine Screw Sizes..

Example: What size bit must be selected to bore a hole for a No. 10 screw. By the table, a No. 10 screw is .18944" in diameter. By the table of Fractional Equivalents for Decimal Values it will be seen that a 3/16" bit must be used. The test for gage of screw is always made over the shank just below the head.

Length And Number Of Wire Nails To The Pound

Nails are sold in quantity by the keg, 100 lbs. of nails, exclusive of the keg. Twenty, 30,40,50 and 60d are" base." Other sizes have certain fixed additions per keg to this base price. For example, the price list adopted by manufacturers in 1896 allows an addition per keg of $.70 for 2d common, $.45 for 3d common, etc.

Wire nails are also bought and sold by weight, the size of wire according to the standard wire gage and the length in inches being taken into consideration in specifying the size and in fixing the price per pound.

Common wire nails are thick and have large flat heads. They are used in rough work where strength is desired. Finishing nails are used for fine work such as inside woodwork and cabinet work. Casing nails are somewhat thicker and stronger than finishing nails; they have smaller heads.

Wire Brads

Size, inches..................	½	½	⅝	¾	¾	¾	⅞	⅞	1
Wire Gage, nos...............	20	18	19	19	18	16	18	17	18
Approx. no. brads to lb........	7500	7200	4267	3556	2758	2600	2364	1781	2069
Size, inches..................	1	1	1¼	1¼	1½	1½	1½	1¾	1¾
Wire Gage, nos...............	17	16	17	16	16	15	14	15	14
Approx. no. brads to lb.......	1558	1143	1246	913	761	584	500	500	406
Size, inches..................	2	2	2½	2½	3	3	3	...	...
Wire Gage, nos...............	14	13	13	12	14	12	11	...	...
Approx. no. brads to lb.......	350	268	214	164	150	137	105	...	...

Board Measure Table

Strength Of Materials Yellow Pine Posts

Load in Tons
Length IN FT.	Size in inches
	4x4	5x5	6x6	7x7	8x8	9x9
8	4	5	6	7	8	9
10	3	4	5	6	7	8
12	2	3	4	5	6	7
14.........................	1	2	3	4	5	6
16.........................	...	1	2	3	4	5
18.........................			1	2	3	4

Hard Pine Beams And Girders


Load in Tons
Length IN FT.	Size in inches
	2x6	3x6	4x6	6x6	8x8
6................................	1	1½	2	3	5½
8.................................	¾	1	1½	2½	5
10................................		¾	1	2	4½
12................................		½	1	1½	3
14................................		. .	½	1	2½
16................................			• • a	½	2
18................................					1

STEEL I BEAMS
Load in Tons
Length in ft.	Size in inches
	6	8	12
10....	7	14	18
12....	6	12	16
14....	5	10	14
16....	4	8	12
18....	2	6	10
20....		4	8
22....		2	6
24....		..	4

BRICK PIERS
Load in Tons
Height IN FT.	Size in inches
	6x6	6x8	8x8	8x12	12x12	12x16	16x16
6.........................	2	3	4	5	6	7	9
8.........................	1½	2½	3½	4½	5½	6	8
10.........................	1	2	3	5	5½	6	7

Stresses For Structural Timbers

Working Unit Stresses Used In Dry Locations
	Bending		Compression
Species of Timber	Stress in extreme fibre Lbs. sq. in.	Horizontal shear stress Lbs. sq. in.	Parallel to grain "Short Columns" Lbs. sq. in.	Perpendicular to grain Lbs. sq. in.
*Fir, Douglas -
Dense grade............	1,600	100	1,200	350
Sound grade.........	1,300	85	900	300
Hemlock, eastern.........	1,000	70	700	300
Hemlock, western...........	1,300	75	900	300
Oak.......................	1,400	125	900	400
Pine, eastern white..........	900	80	700	250
Pine, Norway...............	1,100	85	800	300
*Pine, southern yellow Dense grade..............	1,600	125	1,209	350
Sound grade.........	1,300	85	900	300
Spruce.....................	900	70	600	200
Tamarack..............	1,200	95	900	350

* Note: The safe working stresses given in this table are for timbers with defects limited according to the sections on defects in the rules of the Southern Pine Association for Select Structural Material. "Dense" southern yellow pine and "dense" Douglas fir should also conform to the other requirements of this rule. "Sound" southern yellow pine and "sound" Douglas fir require no additional qualifications, whereas the other species should, in addition to being graded for defects, have all pieces of exceptionally low density for the species excluded. •

This table gives working unit stresses for structural timbers used in dry locations, and is compiled in the main from material furnished by the Forest Products Laboratory, Madison, Wis.

Table Of Brick Wall Contents In Number Of Bricks


Seven Bricks to Each Sq. Ft. of Wall Surface
No. OF SQ FT. OF WALL	Thickness
	4"	8"	12'	16"	20"	24"
1....................	7	15	23	30	38	45
2....................	15	30	45	60	75	90
3....................	23	45	68	90	113	135
4....................	30	60	90	120	150	180
5....................	38	75	113	150	188	225
6....................	45	90	135	180	225	270
7....................	53	105	158	210	263	315
8....................	60	120	180	240	300	360
9....................	68	135	203	270	338	405
10....................	75	150	225	300	375	450
20....................	150	300	450	600	750	900
30....................	225	450	675	900	1,125	1,350
40....................	300	600	900	1,200	1,500	1,800
50....................	375	750	1,125	1,500	1,875	2,250
60....................	450	900	1,350	1,800	2,250	2,700
70....................	525	1,050	1,575	2,100	2,625	3,150
80....................	600	1,200	1,800	2,400	3,000	3,600
90....................	675	1,350	2,025	2,700	3,375	4,050
100....................	750	1,500	2,250	3,000	3,750	4,500