Doors and Windows - Window Cranks

I have a bunch of window cranks that are stripped on the inside of the handle and on the actual circular part on the window crank itself. I know you can purchase new crank handles but what about purchasing the circular crank part only. It's gonna be a bigger job if they have to replace the whole piece since they will have to rip the window frame out in order to take our the whole piece. Everything else works fine except for the stripped parts.

You may want to consider drilling through the crank, tapping the hole to fit a set screw (hollow hex), then drilling a slightly larger hole in the ribbed protrusion so the hex set screw will pass into it tightly. This will give you a positive placement of a mechanical fastener and allow the customer to turn and open the windows without spending alot of money replacing the crank mechanisms.