I want to know where to get heat treating oil.

Industrial or food grade?

Used peanut oil from restaurants works well. Smells pretty good too.

I use "store brand" vegetable oil.

Some use automatic transmission fluid.

Veg oil smells like a fish-fry. Tranny fluid smells like... well, a burnt transmission.

If your talking about blades, I always pre-heat the oil before quenching.

Don

vet grade mineral oil from Tractor Supply

Mineral oil works IF you can afford it Ellis custom knife works wells high grade quench oils, among other things.

Ellis Custom Knifeworks - Custom Knives, Straight Razors, Forges, Refractory, and Knifemaking Supplies

Ya, it's pretty expensive, about $14 a gallon.

Jim, where abouts in the world are you? Certainly here in teh UK it's not that easy to get hold of compared to the US (at least that's the impression I get). Before I found a supply of commercial HT oil I used peanut oil with very good results (though it depnds on the speed of quench that you are aftr )

Olive - smells like ollebolen MMMMMM MMMMMMM

I have a new five gallon bucket of hydraulic oil. It was supposed to be hydraulic fluid for the tractor but wasn't. It is open and I have to keep it. Could this be used as a quench oil???
Jerry

what kind of oil is it ?or the specs that could help

The label reads;
Hydraulic oil - multipurpose formulation
Meets or exceeds - Dennison HF-0, HF-2, cincinnati Milacron P-68, P-69, P-70 & ASTM D-2882 Vane Pump Ware Tests.

I get mine out of my oil pan when I change my oil in my truck. Nothing like 15w40 for a quench. Cheap.

It's also a good excuse to fry a turkey this year! that's where I got my peanut oil a few years ago, still works fine :)