>>278218yea...I use a backyard method that works great.
generally it gets them hard enough you can't drill through them with a carbine drill bit afterwards.
really just charcoal with a squirrel fan blowing from underneath. test with magnet once its a temp then quickly quench on veg oil. its not professional grade results but rarely do people need that level of exact results unless you're a professional or commercial knife maker.
I temper in the oven at 400 degrees for thirty minutes to soften it back up a bit to put the final edge on.
granted more complex metals cannot be heat treated this way. that method really only works for 1095..5160 and 440c or Aebl in my experience
