Installation and removal of fasteners (160103h)

Question 1

What are designed to chase damaged external threads, but not to cut new threads? Why are they designed for use on only damaged threads?

Answer 1

Die nuts are designed to chase damaged external threads, not to cut new threads, as they are not adjustable.

Question 2

You should turn shaft in a lathe while using a thread file to chase threads.

Answer 2

False. If you turn the shaft while filing, you also remove material from the undamaged threads.

Question 3

Describe five ways of removing a seized nut.

Answer 3

• Penetrating oil if the nut is rusty.
• Apply heat to loosen thread-locking compounds.
• Use a nut splitter to cut the nut off.
• Use a hammer and chisel to cut the nut off.
• Use a hacksaw to cut the nut close to the mating thread.

Question 4

For what does EDM stands?

Answer 4

Electrical discharge machine

Question 5

An EDM is a good machine for removing studs broken off deep in a hole. True or false

Answer 5

True

Question 6

Thread-restoring inserts can provide stronger threads in soft or weak materials. True or false

Answer 6

True

Question 7

After installation, the locking key on a solid threaded insert is broken off. True or false

Answer 7

False. They help lock the insert in place.

Question 8

The yield point is reached just before the elastic limit of the fastener material. True or false

Answer 8

False. The yield point is just beyond the elastic limit of the fastener material and lower than the tensile strength.

Question 9

Bolts and nuts are ________ to a certain ________ to keep them tight after the load is added.

Answer 9

Bolts and nuts are torqued to a certain preload to keep them tight after the load is added.

Question 10

If the bolt threads are elongated, the full tensile load falls on _______ of the nut.

Answer 10

If the bolt threads are elongated, the full tensile load falls on the first one or two threads of the nut.

Question 11

A nonheat-thread nut is strong enough for most tensioning applications. True or false

Answer 11

True

Question 12

How is the bolt tensioned in a hydraulic tensioning set-up?

Answer 12

A jacking tool screws onto end of the bolt, which requires some additional thread protruding out of the nut at one end by about 1 to 1 ½ times the bolt diameter.

Question 13

All lubricants reduce the required torque by the same amount. You can use anything. True or false

Answer 13

False. Different lubricants reduce the required torque by different amounts. They all have different lubricity. Only the recommended lubricant should be used.

Question 14

What is the main purpose of lockwiring?

Answer 14

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

Question 15

Left-handed threaded bolts are lockwired the same as right-hand threaded bolts. True or false.

Answer 15

False. All operations referring to CW or CCW should be reversed for fasteners with left-handed threads. Instead of 2 to 6 o’clock, the hole position must be in the 6 to 10 o’clock position.

Question 16

Applying lubricant to the thread of a fastener _______

Answer 16

increases the clamp load compared to dry threads.