Threads Flashcards
What differentiates a bolt from a screw?
A bolt has a nut on the end and a screw goes into a bottom out hole.
What are the four types of bolts
Square, hex, plow, carriage
What size do machine screws go up too?
3/4 inch is the biggest
What are threaded inserts called?
Heli coil
In unified thread classes how are the fit classes identified?
Class 3A,3B class 2A,2B class 1A,1B (there is class 4,5,6 but seldom see them)
In ISO metric thread classes how are they identified?
They are stated in letter and number form (example is 6g or 4h)
What is the taper on a NPT?
3/4 of an inch per foot
What is an ACME thread angle?
29 degrees
What are brown and sharpe threads used for?
used as a drive to turn a worm gear
what angle are brown and sharp threads cut to?
29 degrees
How do you calculate metric machine screws OD??
multipy the screw number by thirteen thou (0.013) and then add+ sixty thou (0.060)
Studs have a course end and a course end?? T or F
True: The course threads provide an interference fir to ensure only the nut on the fine thread comes off when loosened
How do unified threads divide their classes?
It uses its allowance and tolerance?
What is allowance vs’s tolerance?
Allowance is the predetermined sizes and clearances set for two threads to fit, tolerance is the amount plus or minus from those allowances the part can be made (also LMC and MMC)
What is LMC and MMC?
Lower material condition is the smallest amount a part can be to fit the tolerance and Maximum material condition is how big the part can be to fit in the tolerance
