Grinding on some crow bars and other sharps...when do temper issues come into play

[T-Dog]

I have had to take some poorly designed, poorly executed and abused tools including some garden knives into the shop for some repair and on some of them I have had to take a fair amount of steel off and I have been taking it really slow using a lapping type abrasive wheel since I know the heat can build super fast with a standard grinding wheel and I am curious how hot it has to get before you start jacking the temper? Do you really have to bear into it and get things pretty spicy to mess it up such as too hot to put your hand on it or is the damage point much lower?

 

[brets-ftw]

the rule of thumb I go by is if you see color change on the bare steel, you're messing with the temper.

 

[cpmsteel]

Yeah if it changes color your changing the temper. Yes if it's too hot touch, it's getting hotter than I like my knives to get. Keep a bucket of water next to you and dunk it when it gets to hot to touch, or before.

 

[spareparts]

Listen to your hands. If it's too hot to touch then cool the steel down by a dunk in some water.

 

[Stacy E. Apelt - Bladesmith]

The edge will have to get above 400°F to affect the temper.
Be aware that the thinner edge can become many times hotter than the blade in an instant. Long before your hands say "HOT" the edge may be hitting 500-600°F and turning blue.

 

[T-Dog]

good point on the thin sections of steel....thanks for the help all