Well, now you need to harden that punch bit so that it will punch maille! So, hold it in a pair of pliers and heat it to orange heat, and plunge it into cold water. This hardens the punch:
After you've done this, grind the side of the punch (where you've already ground a face) just lightly (not heavy enough to generate heat) so that it becomes shiny metal again.
Then, heat the punch with the torch again, just until the shiny spot you ground starts to turn blue! Then plunge it into the cold water again. This tempers the punch.
Now set the punch bit into the tongs. The "slice" of the punch should be in-line with the arc the tongs sweep as the close. In other words the punch should cut though the air as if you were swinging a sword. If you put the tong in 90 degrees to that, it will break if you try and use it.
Well, like I said, put the bit in place. Tighten up your set screw so it doesn't go anywhere. Then take your punch receptacle and thread it so that about a quarter of an inch stands out of the tong jaws. Then squeeze the tongs together, so that the punch bit tip just scratches the surface of the punch receptacle face. Don't squeeze hard or you will ruin the bit and have to start over with it. You just want to make a scratch on the face of the punch receptacle so you know where to drill the receptacle pocket.
Then remove the receptacle and drill it with a small drill bit. 1/16" works great. A drill press is almost a necessity here. It would be very easy to break the bit otherwise. Use the drill to drill a pocket into the face of the punch receptacle, right where your scratch is. Drill it about 1/4"deep. Since we’ve already annealed the receptacle screw (see above) it should drill fairly easily.
Then put the receptacle back into the tongs. Squeeze the tongs gently together. The point of the bit should go down into the receptacle hole. Gently squeeze a little harder. The sides of the punch should indent the receptacle hole slightly. Now take the punch receptacle back out, heat it to orange heat, and plunge it into cold water, quench hardening it.
Slip the handles (that we saved earlier) back onto the handles. Your tongs are now ready to use.