7.5 PRACTICE PROBLEMS
1. What would happen if a drill without flutes was used?
2. If we want a hole with a 1/2-14-UNC thread, what size of tap drill should be used?
3. What type of drill press is suitable for drilling holes in car engine blocks? Justify your answer.
4. Which of these statements is not correct?
5. Which of these statements is correct?
6. Which of the following statements is not correct?
7. Which of the following is not a typical drill press operation?
8. Which of the statements is most correct?
9. Given a hole that is to be drilled then reamed to 3.000", develop a process plan including speeds and feeds.
10. We want to drill a hole that is 2.369" in diameter. If we know that the accuracy the shop can provide for drilling is +0.030" to -0.010",
11. Calculate the machine tool spindle speeds for the following,
12. We are to drill 6 holes in a 2" thick mild steel plate. The plate is held in a jig. We are using a 63/64" high speed steel drill, and the suggested parameters are CS = 80 ft./min. with a feed of 0.004"/rev. After drilling each hole is to be finished with a 1.0" diameter reamer. If the suggested parameters for the reamer are CS = 80 ft./min. with a feed of 0.010"/rev.,
b) find the cost to produce 500 parts when each part needs 3 minutes for setup (no operation), labor rates are $25/hr., and overhead is $25/hr.
13. Which of these statements is not correct?
14. Which of these statements is correct?
15. Which of the following statements is not correct?
16. Which of the following is not a typical drill press operation?
17. Which of the statements is most correct?
18. What are functions of the following parts of a drill bit. a) body, b) web, c) point, d) tang, e) margin, f) flutes, g) body clearance.
19. What are the purposes of the following drill points. a) conventional, b) flat, c) long angle.
20. What applications are the following drill bits well suited to? a) high helix, b) straight flute, c) gun, d) hard steel, e) core, f) oil hole.
21. What will happen if a drill bit has unequal angles on the cutting edges/lips? What if the edges are not of equal length?
22. Why should most holes be started with a center drill?
23. What are the disadvantages of a thick web found on some drills?
24. What is the purpose of pilot holes?
25. What is the main difference between a) threading operations and tapping operations? b) boring and reaming?
26. List 5 ways work can be held in a lathe.
27. Can peripheral and face milling be done with the same cutter? How common is this?
28. Describe the steps in cutting a 3/8-12-UNC taped hole.
(ans. center drill, drill 1/4", drill .292", starting tap, finishing tap)
29. a) Explain the cutting mechanism of a drill bit, and b) suggest the features of a drill bit for cutting a thin piece of sheet metal.