PSA: Overheard a guy at the scrap yard say he quenches his punches in used motor oil

I was picking up some steel in Toledo last week and this older smith was telling his buddy he keeps a bucket of old car oil just for quenching his center punches and drifts. He said it cools slower than water, so it's less likely to crack the tool steel. I tried it on a punch I made from an old coil spring, letting it soak for about 20 minutes in the hot oil after the quench. The temper came out way more even, with less stress. Has anyone else tried this with specific tools, or do you stick with water or commercial quenchant?

2 comments

2 Comments

max2732d ago

My uncle used to do that with his old truck oil for cold chisels. It leaves a gnarly black scale you have to wire brush off, but he swore it made them less brittle. I still use water for most punches because it's free and right there.

miles_campbell392d ago

That "free and right there" thing @max273 said is so true! I see it everywhere, people using what's handy even if it's a bit messy. My neighbor fixes everything with duct tape for the same reason.