Draw Tempering Question

go mike

go mike

Joined
Dec 5, 2008
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Okay, I'm in the process of making four camp knives, and I need to heat treat them as soon as I can. (Preferably tomorrow morning). The steel is admiral's 1084 HR, and I have yet to drill pin holes. I have not had success with annealing the stuff yet, because I don't have a forge yet, so I still HT using blow torches.

Okay, here come the questions:
•Would using a torch to "temper" the handle area past the temper colors (back to the grays) act as annealing to be able to drill through it?
•If so, I would expect that I should "temper" the handle and let it cool BEFORE I HT the blade?
•Do I air-cool the handle, or do I quench it when it is around 1000 degrees?

P.S. I've already ground the bevels on the blades, so the next step would be drilling the holes or heat treating the blade.
 
Well, as you have said it won't be a proper HT, but your basic plan will make a knife from 1084.

Start with the handle. Heat it (with the torch) to just below non-magnetic. About 1200F is where you want to be. This is a medium red color. Let it cool to room temp. Check that it is softened and drill your holes.

Once the handle is ready, time to HT the blade. Using the torch ( and holding the tang in long pliers or some tongs) heat the blade as evenly as possible so it gets non-magnetic. This will occur around 1350F. Heat it a little more, trying to assure that the whole blade is the same all the way to the handle. Quench in oil (a gallon of peanut or canola will work fine). Pull out after about eight to ten seconds and check for warpage.The blade is hot ,be careful! Immediately straighten with pliers, a vise, gloved hands, or on an anvil. Don't take more than ten seconds to do it or the blade will be getting too brittle. You have to have any bending/straightening done before the blade drops below 400F. If the blade starts to feel hard...quit straightening. If there is too much of a warp, just re-anneal,straighten, and re-do the HT.

Check the edge with a file to see that it got hard. If all is well, clean off and place in the kitchen oven at 425F for two hours. Take out and cool off for about five or ten minutes, then put back in for another two hours.

Sand the blade off until the steel is shiny. Take your torch and draw the spine ( run the torch flame along the spine only) until the yellow color walks to about 1/2" from the edge. Quench the edge in water as needed to control the temper. Now, take the blade by the tip and heat the handle area with the torch allowing the yellow color to walk down to the ricasso. Quench in water immediately when it gets there. It is OK if the rest of the haqndle gets a blue color, but don't make it get red. Take your time and heat slowly. You are only trying to get the steel to about 600F.

If all went well you will have a blade with a hard edge, a tough spine, and a softer handle. The place that gets short-changed in torch HT is the ricasso/handle area. It often is a mix of structures, and if not paid attention to in the HT, can end up too brittle, causing the blade to snap right at the handle in use.

Hope this helps some.
Stacy
 
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