non threaded fasteners and locking devices Flashcards
what is a rivet
soft metal pin on one end that fastens parts together permanently
six common rivet heads
oval
oval countersunk
flat
flat countersunk
button
truss
what are rivets used for
quick and low cost joining/repair
how are rivets measured
by the weight per 1000
ex. 1000 rivets that weigh 6 ounces, each rivet is called 6 ounces
small solid rivets are available in what types of metals
steel
aluminum
brass
copper
what are the uses of solid rivets
vehicle frames
cross members
heat from hot solid rivets can cause what
structural damage
what is the most common rivets
semi tubular rivets
what are compression rivets
are male and female and usually have flat heads
where are tubular rivets used
they appear in high volume production lines with automated riveting machines
what are self piercing rivets
are machine rivets that make their own hole in the material they are joining
three general categories of tubular rivets
semi tubular
compression
self piercing
blind rivets are used for what
light duty use and easy, low cost method
what are structural breakstem rivets
are high performance, flush break blind fasteners
they break off flush when stretched
what are explosive rivets
good for blind application. they detonate a small explosion charge
what is the strongest structural breakstem fasteners
lockbolt fasteners
when mating a hub or gear with shaft what do you use
key
what is the groove in a hub called where you put a key
keyway
what is the groove in a shaft called where you put a key
keyseat
when a hub and a shaft are subject to very heavy loads what should you do
use a chamfered key and a filleted keyway or keyseat
woodruff keys are used for what
lighter application such as small pulleys or gears
a key should have what clearance
0.002 to 0.005 inch
when are Pratt and Whitney keys used
when a hub slides back a forth on shaft
square keys are used up to what size diameter
6 inch
flat keys are over what size diameter
6 inch
a square and a flat key should be what diameter of the shaft
1/4
if a shaft is 3 inches what square or flat size key would you use
3/4
what do the first two digits of a woodruff key give you
the width in thirty-seconds of an inch
what do the last two digits give you in a woodruff key
the diameter in eighths of an inch
taper keys have what taper per foot
1/8
what is the main purpose of a gib head key
to lock the hub the the shaft in heavy loading conditions
What are splines used for
External grooves and lands machined on a shaft to match with internal grooves and lands inside a gear, collar, sleeve or coupling
What are dowel pins grounded to?
0.0002 inch over nominal diameter
When are tapered dowel pins used
They are for use when precise location is a requirement or with the frequent assembly and disassembly of parts
What are shear pins used for
They are used to connect a gear or other part to a shaft designed to disconnect on overload
Two types of radial locking pins
Solid grooved pins
Hollow roll or spring pin
What do snap rings do?
Snap rings provide a removable shoulder to locate, retain or lock components accurately on shafts, bores and inside housings
What self-locking ring is better? Internal or external?
Internal because it covers more diameter on the workpiece to hold it together
