threaded fasteners and locking devices Flashcards
what is a bolt
is a fastener used with a nut
what is a screw
threads into a mating part
the term threaded fasteners include
bolts
nuts
screws
studs
threaded inserts
machine bolts are what diameter
1/4 inch to 1 1/2 inch
machine bolt shanks are usually slightly larger than what
the nominal size of the bolt
what are cap screws made of
high tensile steel
what are the markings on the top of a hex head used for
indicate tensile strength
nuts are sized according to what
bolt thread size
two properties of nuts
nut height
wall thickness
lock nuts with radially cut notches are used for what
bearing assembly with tab washers and tapered sleeves to locate bearings on shafts
what kind of screws are less than 1/4 inch in diameter and never larger than 3/4 inch
machine screw
most machine screw heads are what styles
round
flat
oval
standard counter sink angle on a machine screw
82 degrees
set screws are commonly used to retain what
hub
collar
gear
sleeve
what are studs
cylindrical shafts that are threaded on both ends
thread cutting screws are used for what
assemble sheet metal
plastics
and soft metals such as brass and aluminum
what are the ends call on a stud
metal end (threads on workpiece)
nut end (goes through clearance hole in a mating part)
two families of self threading screws
thread forming screw
thread cutting screw
thread forming screws are used for what
cut threads in the parent material
aluminum
zinc
steel sheets
cast iron
brass or plastic
when using 2 set screws to hold a hub onto a shaft without a keyway they should be at what angle from each other
90 degree
why are thread forming screws used
they are convenient in sheet metal assemblies
name two tapered thread forms.
national pipe taper
dry seal national pipe taper fuel
American petroleum institute
thread comparison gauges use the what as a basis for thread size
pitch diameter
thread angle from an American national acme thread is what
29 degrees
classes 2A and 2B are used for what
general purpose
what is pitch diameter
is diameter at which the thread thickness equals the thickness of the space between threads
classes 3A and 3B are used for what
aerospace and precision tool application
classes 1A and 1B are used what what
where thread parts must be assembled quick and easy
the fit of a screw refers to what
how much play between mating nuts and bolts.
