Regrinding a 118 degree drill to 135 degrees

[woodchucker]

You really needn't be concerned about quenching while grinding HSS. Even less for M42.

M2 HSS has a tempering temperature of more than 1025ºF, at which point, it will be beginning to glow. The point at which it begins to lose hardness is around 1150º and is definitely glowing.

I think most of us quench to be able to hold it. Doing it on cast steel can/will cause it to fracture... so don't.

 

[benmychree]

You really needn't be concerned about quenching while grinding HSS. Even less for M42.

M2 HSS has a tempering temperature of more than 1025ºF, at which point, it will be beginning to glow. The point at which it begins to lose hardness is around 1150º and is definitely glowing.

Yes, not much worry about overheating HSS when grinding, quenching from higher temperatures can cause fine cracking resulting if cutting edge breaking down, only (other) drawback to not keeping the point cool is burning your fingers.