Find your keys; square, flat, gib-head, round...

[mklotz]

FWIW, there are two programs on my webpage which relate to keyway calculations - KEYWAY and OFFKEY.

The former implements some typical square keyseat calculations. The latter, requested by a user, assists in the design of an offset key. I'm not familiar with offset keys but the idea is that if a small angular offset of the shaft position is needed after the keyways in shaft and bushing/pulley/etc. have been cut, a key that has the parts that enter the two slots angularly displaced is employed. An interesting bit of math goes into designing such a key.