I have to remove a crank sprocket (other car) that's stuck solid, in order to replace the oil seal that's behind it. My plan is to drill some 5mm holes in the sprocket, so that it gives way (don't like grinding: too brutal
)
This sprocket looks like it's made of hardened steel, so the regular HSS bits won't work I guess.
I've heard of these cobalt drill bits, can someone recommend these, or even better ones for this job ??
Thanks,
V.