Materials & Processes

Question 1

2. List the steps in a dye penetrant inspection?

Answer 1

1. Thoroughly clean the materials surface
2. Apply the penetrant for the specified dwell time
3. Remove the penetrant with water or emulsifying cleaner
4. Dry the part
5. Apply the developer
6. Inspect the results

Question 2

3. Describe the procedure for performing a magnetic particle inspection.

Answer 2

1. Clean the ferrous material thoroughly
2. Magnetize the part & apply ferromagnetic particles, either held in liquid suspension or dry powder
3. If a discontinuity is present the magnetized particles will form a pattern in the shape of the discontinuity

Question 3

4. What are two types of self locking nuts?

Answer 3

All metal and fiber lock or elastic stop nuts

Question 4

5. What is the general rule for using self locking nuts?

Answer 4

Do not use at joints subject to rotation

Question 5

6. What type of cable is used in primary control systems?

Answer 5

Extra flexible 7x19 cable

Question 6

7. How can the correct “grip length” of a bolt be determined?

Answer 6

Equals the total thickness of the material being joined

Question 7

8. The length of AN standard bolts are measured in what fraction?

Answer 7

8ths of an inch

Question 8

9. What does the triangle mean on the head of a steel bolt?

Answer 8

Close tolerance bolt

Question 9

10. What numbers are used for close tolerance bolts?

Answer 9

AN-173 through AN-186 for hex bolts

NAS-80 through NAS-86 for countersunk

Question 10

11. What is the difference between a standard bolt and close tolerance bolt?

Answer 10

Close tolerance bolt is machined more precise and used in high performance applications

Question 11

12. A solid rivet diameter is always measured in what fraction?

Answer 11

32nds of an inch

Question 12

14. What is the purpose of a channel nut and nut plate?

Answer 12

Both nuts allow a screw or bolt to be installed without holding the nut

Question 13

15. What are common materials for cotter pins to be made from?

Answer 13

Low carbon steel & stainless steel

Question 14

16. What is the smallest cable that can be used in primary control systems?

Answer 14

1/8 inch diameter

Question 15

17. What should be the depth of penetration when making a fillet weld?

Answer 15

Penetration should be 25-50% of thickness of base metal

Question 16

18. What precision measuring instruments are used to measure outside dimensions?

Answer 16

Outside micrometer & vernier calipers

Question 17

19. What term describes a metal that is based on iron?

Answer 17

Ferrous alloy

Question 18

21. What system is used to identify AN type aircraft bolts?

Answer 18

Aircraft bolts have code markings on bolt heads for identification

Question 19

22. What is the difference between a close tolerance & regular AN bolt?

Answer 19

Close tolerance bolts are used in applications where a bolted joint is subject to severe vibrations and load reversals.

Question 20

23. What are the steps for solution heat treating aluminum alloys?

Answer 20

1. Heated
2. Heat soaked
3. Rapidly quenched to a low temperature

Question 21

24. In what state is aluminum alloy immediately after solution heat treating and quenching?

Answer 21

Alloy is in a soft state, so the material must be naturally aged, or precipitation hardened

Question 22

25. What is done to prevent certain aluminum alloy rivets (D and DD) from becoming hard after heat treating and quenching?

Answer 22

stored in a refrigerator at temperature lower than 32 degrees F.

Question 23

26. What do rivet head markings indicate?

Answer 23

Alloy of the rivet

Question 24

27. Why is alloy steel that is responsive to heat treatment usually less suitable for welding?

Answer 24

Becomes brittle & looses its ductility around the weld

Question 25

28. Why should steel be normalized after welding or machining?

Answer 25

To remove internal stresses of the metal, reducing brittleness

Question 26

29. What are two methods of case hardening?

Answer 26

Carburizing and nitriding

Question 27

30. What are the characteristics of cold weld?

Answer 27

Has improper penetration & cold laps caused by insufficient heat

Question 28

31. What tools are used to measure the outside dimensions of shafts, thickness of sheet metal stock, diameter of drills, and for many other similar applications?

Answer 28

Outside micrometer or caliper

Question 29

32. What should be used to make a visual inspection of a weld?

Answer 29

Magnifying glass of at leas 10x

Question 30

33. Name some types of non-destructive testing used on non-ferrous materials.

Answer 30

Eddy currents
Dye penetrant
X-ray
Coin tap
Visual inspection

Question 31

34. What is the most common type of corrosion?

Answer 31

Surface corrosion

Question 32

35. What does a 1/4 -20 bolt mean?

Answer 32

Bolt diameter and thread count

Question 33

36. Why should a micrometer be periodically calibrated?

Answer 33

Helps ensure micrometer accuracy

Question 34

37. A solid rivets length is measure in what fractional increments?

Answer 34

16ths of an inch

Question 35

38. What are some types of washer used on aircraft?

Answer 35

Flat washer
Tab washer
Finishing washer
Spring lock washer
Lock tooth washer

Question 36

39. What is M.S.D.S/S.D.S.?

Answer 36

Material Safety Data Sheets/ Safety Data Sheets