> It's hard to do irreparable damage to the steel of a knife. It’s easy — just heat it above the tempering temperature of the steel in question. You can achie

> It's hard to do irreparable damage to the steel of a knife. It’s easy — just heat it above the tempering temperature of the steel in question. You can achieve this in an ordinary oven for most steels, and you can also achieve it (locally) with a motorized sharpener that isn’t cooled. Don’t take a knife you care about to be professionally sharpened by a person who uses a non-water-cooled power tool.