Shoutout to the old timer who showed me how to quench in warm oil instead of cold

After 8 years of using cold canola oil and getting inconsistent hardness on my knife blades, I switched to warming it to 130 degrees and now my edge retention on 1095 steel went from 50 chops through a 2x4 to about 120 before dulling - anyone else notice a big difference with oil temp on their quenches?

3 comments

3 Comments

viola_ward1mo ago

Yeah, I mean, warm versus cold is honestly a total game changer but it took me forever to even try it because everyone online says "just get it hot enough to catch fire" or some macho nonsense like that. Eight years is a long time to be doing it wrong, I did about four years with cold canola and my edges were just hit or miss, mostly miss. Now I get it, warm oil lets the steel actually move before it hardens so you don't get those brittle spots or soft patches. But like, my first few attempts with warm oil I panicked and pulled the blade out too fast because I thought I was going to ruin it. Anyway, 120 chops versus 50 sounds about right, it's like night and day once you dial in that temp.

rowanharris1mo ago

I get what you're saying but I have to disagree a bit. Warm oil works great for some steels sure, but cold canola has always treated me fine if you know what you're doing with your preheat and soak times. I think the whole "warm vs cold" thing gets blown out of proportion because people mess up their normalizing cycles or rush the quench. You mentioned pulling it out too fast, that's the real issue not the oil temp. If your blade has thin edges and you're using a fast oil like canola at 120 degrees, you're way more likely to crack something than if you kept it at 70 and just let it sit. I've done hundreds of blades with room temp oil and never had soft spots because I make sure my austenitizing temp is dialed in and I don't rush the cool down. Different strokes I guess but cold oil never let me down.

taraanderson24d ago

Totally agree. Cold canola works fine if you don't panic and pull too early.