Non-threaded fasteners and locking devices (160103g)

Question 1

A rivet is:

Answer 1

a permanent fastener.

Question 2

What is a taper per foot of a tapered gib head key?

Answer 2

1/8 inch taper per foot

Question 3

What is the taper per foot of a tapered dowel pin?

Answer 3

1/4 inch taper per foot

Question 4

Why are rivets used? And what type of materials are they used on.

Answer 4

Rivets are useful for quick, low cost joining and repair of sheet metal, plastic, fabric and belting and where bolts or screws would be impractical.

Question 5

What type of material is coil type inserts used on? Explain the reason they are used.

Answer 5

Used on aluminum castings, making the threads harder, tougher, smoother and more wear-resistant.

Question 6

What is the most common rivet used and give a brief description?

Answer 6

Semi-tubular rivets have short tubular bores that have all the compressive strength and shear strength of solid rivets when they are clinched.

Question 7

How should a key fit a shaft? How much clearance on the top of key to hub?

Answer 7

The key should be a tight fit into the keyway and keyseat. The key should have 0.002-inch to 0.005-inch clearance on top and fit tight on the sides.

Question 8

What size shaft is a flat key used on?

Answer 8

Flat keys are used on shafts over 6 inches.

Question 9

What key would you use on a 3” shaft?

Answer 9

Square key

Question 10

What key is used when the hub slides on the shaft?

Answer 10

Pratt and Whitney keys

Question 11

What material would you not use a gib head key?

Answer 11

Cast iron

Question 12

What are dowel pins not used for?

Answer 12

Not for holding the parts in place

Question 13

What are the 2 reasons to use tapered dowel pins?

Answer 13

• When precise location is required

- When frequent assembly and disassembly is needed

Question 14

Shear pins are designed to break. Give 2 reasons why.

Answer 14

• To prevent overloads in drive mechanisms

- For safety purposes

Question 15

Is it recommended to reuse cotter pins?

Answer 15

No

Question 16

What kind of washer is used in bearing assembly’s where positive location is important?

Answer 16

Tab washer

Question 17

Where are beveled washers used?

Answer 17

Beveled washers are common with structural steel components, such as I-beams.

Question 18

How does Anaerobic sealant work?

Answer 18

When exposed to air, aerobic sealants cure to form a firm flexible rubberized seal.

Question 19

How much taper does a tapered dowel have per foot?

Answer 19

1/4 inch taper per foot

Question 20

How much taper does a gib head key have per foot?

Answer 20

1/8 inch taper per foot

Question 21

With a bolt having a tensile strength over 150000 psi, what nut would you use?

Answer 21

High carbon heat-treated nut, Grade 8 and higher

Question 22

Which thread has the greatest strength, a fine or course thread?

Answer 22

Coarse thread

Question 23

What is the purpose of wire locking?

Answer 23

Lockwiring is used to prevent fasteners from coming apart and falling off into nearby machinery.

Question 24

What is the purpose of thread restoring inserts?

Answer 24

To restore damaged or stripped threads and to provide strong threads in soft or weak materials