bolts
keys
cotters
rivets
d
1.25 d
1.5 d
1.75 d
0.2
0.25
0.5
0.6
tensile strength
compressive strength
shear strength
bending strength
one smaller nut is tightened over main nut and main nut tightened against smaller one by loosening, creating friction jamming
a slot is cut partly in middle of nut and then slot reduced by tightening a screw
a hard fiber or nylon cotter is recessed in the nut and becomes threaded as the nut is screwed on the bolt causing a tight grip
through slots are made at top and a cotter-pin is passed through these and a hole in the bolt, and cotter spitted and bent in reverse direction at other end