Does anyone have experience using Soybean oil for heat treating hammers and punches?

I use canola oil on punches and small parts. I haven't needed to heat treat a big part yet. Other people use peanut oil or other vegetable oils so I am sure that soy will work fine. Generally speaking you want a gallon of oil per pound of steel, and you want the oil warm to start with, and a lid in case of flame. Soybean oil has a higher smoke point than peanut oil. (soy 495F, peanut 437F)

Phil

I'm pretty confident it'll work fine. If anything it may be faster than 4140 requires. However, I have no experience using soybean oil as a quenchant for anything.

I use peanut oil in a 7 gallon metal barrel with lid for anything needing an oil quench. Soy oil should work just fine. During the colder months, I put the barrel on top of the woodstove to heat up. On Summer's Day, no need to prewarm it.

I think the problem is that the soybean oil will probably become rancid over time. I like atf 4:1 with diesel to cut the flash.
JE

From the horses mouth;

http://www.crucible.com/eselector/prodbyapp/carbon/maxtool.html

The soybean oil is OK, so long as the parts are not too small or complex. ATF would be a safer option if they are.

Cheers,

Nick