For a cotterkey joint, curl the cotterkey down
(like a can of canned ham). You can use needle nose pliers OR
for added convenience, use a cotterkey turning tool.
Cotterkey turning tool
For a nut & bolt joint, place the self-locking nut on the
bolt. Tighten the nut using a socket wrench. Hold the other
end of the bolt with a screwdriver while you tighten the lock
nut. NOTE: If you like, you can glue the bolt in place with
epoxy glue. This eliminates the need to have a screw driver
to hold the bolt still. You can simply hold the hard board disc
and use the socket wrench to tighten the joint.