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