arbor
axis
axle
axle bar
axle shaft
axle spindle
axle-tree
distaff
fulcrum
gimbal
gudgeon
hinge
hingle
hub
mandrel
nave
oarlock
pin
pivot
pole
radiant
rowlock
spindle
swivel
trunnion
amatuer
backplate
base plate
bipod
carabiner
clevis
dead-bolt
deadbolt
detent
diffuser
firing pin
forend
leadscrew
lube
quick-disconnect
red light
restrictor
rotator
umbilical