My old mentor in Boise insisted I quench my first knife blade in used motor oil, and now it's got a hairline crack running from the tang.

Has anyone else had a specific quenching medium fail them like that, and what do you actually use for 1080 steel?

3 comments

3 Comments

So what was his reasoning for using old oil in the first place? I mean, even if you didn't know the science, it just sounds like a bad idea. It's dirty and cools all wrong for a good blade. Did he ever give a real explanation, or was it just some old shop lore he never questioned?

the_william2mo ago

Used motor oil is a terrible quenchant for 1080.

wendy6282mo ago

Yeah, my buddy tried quenching a 1080 knife in old motor oil once. It came out with this weird, soft skin and a bunch of gunk stuck to it, just like @the_william says. He had to grind it all off and start the heat treat over with proper quench oil. Total waste of a weekend.