There is NO reason to heat treat the tang of a knife blade that hold the handle to the cutting edge of the knife.
However, commercial knife blades are mass made, and mass heat treated, so you get tangs that are hard as the blade is.
To DRILL the tang for the handle cross-pins:
1. Clamp the blade into the jaws of a bench vise. The jaws will act as a heat SINK, drawing heat away from the blade. Have the tang you want to drill above the top of the jaws of the bench vise. If you have a tang longer than 3 inches, then "choke up" on the tang when drilling pin holes in the upper portion of the tang.
2. Now, heat that tang up RED HOT. I use a propane torch, but a Mapp Gas torch, or Acetylene Torch will do the job as well.
3. Drill the holes for the pins when the metal is Red hot. A standard high carbon drill bit will cut through the toughest steel as if you were drilling balsa wood.Have a friend or relative stand by to put oil on the drill bit so it doesn't over heat, but if alone, put oil on the flutes of the bit before you begin to drill. It simply takes only seconds to put the hole through the tang.
4. I leave the tang return to room temperature in the vise. The Alloy steel( stainless steel?) tangs remain tough, and hard. But, I suppose, if you are going to worry about heat getting down to the blade, then take a wet- very wet-- rag and slap in onto the tang to cool it rapidly.
I bought several "laminated steel" blades from a company that advertised in Muzzle Blasts, more than 30 years ago, and made two "patch knives" with them, and some antler tines I had. I burned up a Carbon steel drill bit trying to drill the holes after using a center punch to mark the holes. I also hurt my arm, shoulder, and back pushing so hard I actually rocked my work bench up with about 300 lbs. of bricks sitting on the lower shelf to hold it down. The next day, I drove to a hardware store, where I visited the " Commercial Counter"- the area set aside to service building contractors. The clerk there recommend several different bits, including one- a very EXPENSIVE ONE-- with a Carbide TIP on it, to try. I bought 4 bits- one to replace the one I ruined, one to use on this project, again( and assuming I ruined it to throw away) a much more expensive, high carbon drill bit, and the carbide bit.
On the way home, I recalled watching a Wheelwright demonstrating how he put a steel tire on a wooden wagon wheel, at the Lincoln Homestead South of Charleston, Illinois. He heated the 1/4" thick steel "tire" up in his forge, and then PUNCHED a hole into the end of the strip using a punch "hardy", With one HAMMER BLOW per side, or two blows per HOLE! Incredible to see the first time. He was knocking out holes for rivets that he used to join the two ends of the "tire" to make a ring that fit over the wooden wheel frame. Now, he beveled the edges, after the holes were punched, and before the rivets were placed in the tire, and there was much more hammering of that large ring( 48 inch in diameter!) Before he was ready to heat the entire tire up to stretch it over the wood wheel, but I never forgot watching how easily he punched- NOT DRILLED-- the holes for those rivets.
AHA! I decided right then that I was Not going to use those expensive drill bits to drill those hard tangs, until I first tried what I have described above.
IT WORKS. :hatsoff:
