A 1/4" electric die grinder. Harbor Freight has a good one for about $80. But you can find other import brand for as little as $40. And a carbide burr. You can get a set of 6 carbide burrs for $35-$40. Solid carbide will last forever.
If you had a milling machine, you can cut/drill most anything with a carbide bit. Also, when you were trying to enlarge that hole you drilled, try heating the tang of the file up and then placing it in Vermiculite to cool down. Do that 2 or 3 times to anneal the tang, then instead of using that homemade "Punch" as an expander, try heating up the tang and using the horn of the anvil and use small strikes down on the edge of the tang, then use the flat to make it flat again. You can enlarge just about any hole in anything, using that method...! Be sure to rotate the whole knife blank around the horn quickly while taking little "taps" with a medium weight hammer, thinning out the "ring", then flatten it back again on the top of the anvil. (The old saying "If it ain't Glowin', it ain't Movin' !" still applies, especially to high carbon steel. (By the way, that bit you were referring to is called a Rotary Rasp, and "GOOD" ones tipped with Carbide - are Expensive!). Lol...
Now that’s what I’m talking about!!!! Thank you for dropping the knowledge and sharing!!!! Definitely still new to black smithing techniques and knife, making in general love to see the advice in the comments!!! Thanks a million brother!!! 👊
Could start it with a cut off wheel..then maybe a carbide rotary bur.. spot annealing is also an option.. only the cutting edge needs to stay hard.. I've seen pin point torches less then a 1/4 inch for jewelry making that could heat up a tiny spot to anneal it at that area..then drill or grind away..might be able to clamp a cut off grinder stationary and bring the blade to the wheel perhaps..the voice over is creepy ASF..
