Heat Treating

G

Gisxer

Joined
Sep 4, 2015
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So I have recently finished shaping a blade for my first knife to make from scratch, and wanted some advice as far as heat treating is related. I made it from an old Nicholson file for metal. The only heat sources I have readily on hand are a map gas torch, a toaster oven, and a regular oven. Should one of those be sufficient to do the job, or should I see if I can get access to an oxy-acetylene setup? As far as oil goes, I have a bunch of old auto oil (I believe that it is 10W-30) that I could use to cool it. Would that work, or do I need something better? I'm wanting to practice the concept on this knife, before I finish shaping a couple of other knifes that I am about to make from O1. Am I better off just sending all of these off to someone else to treat if I want a good result?
Thanks in advance!
 
A Mapp torch should get a small blade above non-magnetic. An A/O torch with a rosebud tip would be much better. Test the Mapp torch on some scrap first.

Motor oil is a poor quenchant and the fumes are not good for you. Use a gallon of canola oil. Warm it to 120F. Put the oil in a tall metal canister. Do not use plastic or glass.

Temper in the kitchen oven.

Basic HT for a file knife:
Heat the blade evenly as possible until it stops being magnetic. Use a welding magnet or something to check as it heats up. At a medium red color the blade will suddenly stop sticking to the magnet. It is about 1420F at that point. You need to heat it 50-75F hotter (1475-1500f), which will be about one shade of red brighter. Try and get the edge evenly this color and keep it at that temperature for a minute.
Immediately quench in a metal canister of 120F canola oil.
After the blade cools off to room temperature, wash off and place in a pre-heated oven at 400F. bake for one hour, remove and cool off in running water, replace in the oven for a second hour, and remove. The blade is now hardened and tempered.
 
Wow that answered everything for me. Thanks so much! Where would I find a "recipe" for O1 steel?
 
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