Originally Posted by dabac

Hi all,

For some of the dimensions where I don't have proper taps, I've long kept a set of screws/bolts with a notch cut through the threads to clean out grimy and mildly damaged threads.
Considering the entirely marginal cost, they've worked OK.
But I'm thinking of buying some proper taps. Steel-on-steel cleanup performance kinda sucks.

Current considerations:

-derailer hanger thread, M10x1.0
-Square taper crank bolt, M8x1.0