Oils do have there specific applications, I've been through more than one class on oils with the company I use to work for. I'm also picky on what goes in my oil pan on my vehicles and bikes. That said I know there are oils engineered for harding carbon steels, but im sure allot of folks don't have the extra bucks to buy 5 gallons of it. I bet most if not all the knife makers here started out with something else before they got some dedicated quenching oil.......as an update, got the canola oil, heated it to 120 before the quench...........knife turned out great............