fasteners

Question 1

what are designed to chase a damaged external threads but not to cut new threads

Answer 1

die nuts are designed to chase damaged external threads not to cut news threads as they are not adjusted

Question 2

you should turn the shaft in a lathe while using a thread file to chase threads true or false

Answer 2

false. if you turn the shaft while filing you ALso remove material from the undamaged thread

Question 3

describe 5 ways of removing a seized bolt

Answer 3

1. use penetrating oil if the nut is rusty
2. apply heat to loosen thread locking compounds
3. use a nut splitter to cut the nut off.
4. use a hammer and a chisel to cut the nut off
5. use a hacksaw to cut the nut close to the mating thread

Question 4

what does EDM stand for

Answer 4

eletrical discharge machine

Question 5

an ÉDM 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 the lower then tensile strength

Question 9

bolts are nuts are torqued to a certain preload to keep them tight after the load is added

Answer 9

true

Question 10

if the bolt threads are enlongated the full tensile load falls on the first one or two threads of the nut

Answer 10

true

Question 11

a nonheat treated nut is strong enough for most tensioning applications true or false

Answer 11

true

Question 12

a bolt circle requires a torque of 966ft-lb on each bolt if you use four to one multiplier what is the final toque required on each fastener

Answer 12

268 ft per lb

Question 13

how is a bolt tensioned in a hydraulic tensioning setup

Answer 13

a jack tool screws onto one end of the bolt which requires some additional thread protruding out of the nut at one end by about 1 to 1 1/2 times the bolt diameter

Question 14

all lubricants reduce the required torque by the same amount you can use anything true or false

Answer 14

false. different lubriacants reduce the required torque by different ammounts they have different lubricity. only the recomended ones should be used

Question 15

what is the main purpose of lockwiring

Answer 15

lockwiring is used to prevent fasteners from coming apart and falling into nearby machinery

Question 16

left handed threaded bolts are lockwired the same as righthand threaded bolts true or false

Answer 16

false all operations referring to cw or ccw should be reversed for left hand threads instead of 2 to 6 oclock the hole postion is 6 to 10 o clock position

Question 17

the statement that best describes elasiticty

Answer 17

elasticity is the ability to the material to be strecthed and still return to its original shape

Question 18

applying lubricant to the threads of a fastener

Answer 18

increase the clamp load compared to dry threads

Question 19

the difference between a screw and a bolt is the

Answer 19

application

Question 20

why are thread forming screws used

Answer 20

they are convienent in sheet metal assemblies

Question 21

the pitch diameter of a thread is exactly halfway between the major and minor diameters true or false

Answer 21

false the pitch diameter is diameter of the thread thickness equals the thickness of the space between threads it is approximately half way bewtween the major and minor diameters

Question 22

on a general purpose iso metric thread what character in the designation indicattes a medium tolerance grade

Answer 22

number 6

Question 23

name two tapered thread forms

Answer 23

national pipe taper
dryseal national pipe taper fuel
american petroleum institue

Question 24

the unified thread class that offers the tighest fit
6g
2
4h
3

Answer 24

3

Question 25

marks on the head of a bolt indicates the

Answer 25

grade and tensile strength

Question 26

a thread is designated 5/8 - 11 class 2a is a

Answer 26

external thread

Question 27

the thread angle from an american national thread is

Answer 27

29 degrees

Question 28

a no go ring gauge is easily by

Answer 28

a annural ring on the knurrled surface

Question 29

thread camparison gauges used the

Answer 29

pitch diameter

Question 30

rolled threads are advantageous over machined threads because . they have increased tensile strength
they produce a burnished thread finish
they have a better wear resitance which reduces fatigue and shear problems

Answer 30

true

Question 31

the three hand taps found in a set are the

Answer 31

taper plug and bottoming

Question 32

API stands for?

Answer 32

american petroleum insitute

Question 33

a rivet is

Answer 33

a permanent faster

Question 34

what is the taper per foot of a tapered gib head key

Answer 34

1/8 taper per foot

Question 35

what is the taper per foot a tapered dowl pin

Answer 35

1/4 inch taper per foot

Question 36

name the keys in figure 38

Answer 36

woodruff flat gib head pratt and whitney