1. Give the meaning of approximate and precise measurements. Give examples and reasons for employing either method when doing the individual piece of work.
2. When making single-lip drills, why is it necessary to remove exactly one-half the diameter, as shown in Fig. 34.
4. When a mandrel is held in V blocks when laying off the center line, as shown in Fig. 89, how would you find the exact location by precise measurements?
7. Why will a twist drill cut faster and make a truer hole than a flat drill?
8. State in your own language the result attained by using a reamer holder of the design shown in Fig. 80.
9. When extreme accuracy is required, why is it not advisable to grind the essential part of a milling machine arbor before it has the spline cut?
10. Why is it desirable for a tap to retain its correct pitch when hardened? What would be the effect were it to elongate? What if it should contract?
2. Under what circumstances would you consider it advisable to use a counterbore, rather than a drill, when enlarging a hole? Why?
3. Why would it not be considered good practice to turn the piece of stock represented in Fig. 153 to size before drilling the holes and working the slots to size?
4. Why is it not advisable to make a hollow mill, to be used in roughing out work, having more than 4 teeth?
5. Why is it advisable to give a finish hollow mill more than 4 teeth?
8. Give the advantages derived from using a forming tool and holder of the design shown in Fig. 187.
9. Why is a milling-machine cutter more likely to crack when hardening than other forms of tools?
10. Why is it not good practice to ream holes in milling-machine cutters to finish size?
11. What is the result if the hole in a milling-machine cutter does not fit the arbor?
12. When is it advisable to use milling-machine cutters having interlocking teeth?
13. When is it advisable to use milling-machine cutters having their teeth cut spirally? Why?
14. When is it advisable to cut the teeth of milling-machine cutters with a right-hand spiral? When, a left-hand spiral? Why?
1. Why should undue accuracy never be indulged in when making drill jigs and similar tools?
Give examples where extreme accuracy is not desirable. Give examples where it should be observed.
2. When making bushing holes in drill jigs by the method illustrated in Fig. 262, Part II, why are more satisfactory results obtained if the cutting end of counterbore is made of the form shown in Fig. 263?
3. State in your own words the reason for obtaining location of bushing holes in drill jigs by means of locating buttons and lathe indicator.
4. Why are drill jigs for permanent equipment provided with hardened steel bushings?
5. Name the different forms of drill bushings commonly used in jigs.
Name the good features of each.
Name the objectionable features of each.
6. What is the objection to using the ordinary shop mandrel for holding bushings when grinding to finish size?
7. When drilling the block illustrated in Fig. 300, why is it advisable to first use the transfer drill shown in Fig. 303?
8. When reaming the holes in block shown in Fig. 300, why is it advisable to use the piloted single-lip reamer, Fig. 302.
9. Explain the office of the guide and stop used on a punching press blanking die.
1. What points must be considered before designing a tool?
2. What are some of the essentials to be remembered in designing a drilling jig?
3. Why are locking devices important in the design of drilling jigs?
4. Describe the shaving die. Where is it used?
5. What is meant by the term "double action" in a punch press?
6. Make out an "order of operations" for the production of a flat-iron base.
7. What is the object of using hardened bushings in blanking dies?
8. Describe a combination die.
9. Describe a bench micrometer. For what class of work is it used?
10. Name the different classes of gages and their uses.
11. What is an indexing jig?
12. Where is a spring-pump locator used?
13. How are liquid forming dies designed?
14. Why is a relieve cut into the V rest of a V-type jig?
15. Why is it sometimes necessary to design an embossing press and die as shown in Fig. 45?
16. What are the relative positions of the cranks in a double-action press?