My old boss swore by quenching in old motor oil, but it cracked my last three blades.

He said it was the 'secret sauce' for a tough edge and I ran with it for years. Finally tried a proper fast quench oil on a simple 1084 steel knife blank last week. The difference was night and day, no cracks and a way cleaner finish. Anyone got a favorite brand for quenching oil they actually trust?

3 comments

3 Comments

alicemurphy1mo ago

Oh wow, that's rough. Honestly, old motor oil is a gamble because it's full of junk and water. It can cool way too fast and unevenly. Tbh, I've had good luck with Parks 50 for simple steels like that, it's made for the job.

phoenix_bailey1mo agoMost Upvoted

@alicemurphy Parks 50 worked for me too.

gavin4691mo ago

Disagree on the motor oil being the main problem. It's more about the steel and your heat control before the quench. Seen guys use it fine for years when they know what they're doing.