Drilling hardened steel
There is another problem with using already hardened steel as I found out after trying to drill pin holes to secure the handles. I chipped my center punch and believing the punch was at fault I went out and bought an expensive auto punch. Unfortunately the point chipped on it as well after the first mark. Then, while drilling the second hole with a standard hss no. 39 bit, the bit grabbed on break-through and heated the surrounding area burning the steel. Now it dawned on me that both the centre punch and the bit were designed for soft (annealed) steel and the hacksaw blades were too hard for the tools.
Solution:
1. I could anneal the steel by heating it cherry red and slowly cooling it in the hot ashes of a forge. The steel could then be worked and re-hardened and tempered. However, having no idea as to the type of steel, chances are it would be difficult to get the correct hardness/spring back. Many modern steels require super-cooling in liquid nitrogen etc. - way too much like work.
2. I could change the way I mark and drill the already hardened steel. Marking the drill points is not necessary if you use the correct drill. A cobalt or tungsten bit will drill hardened steel, but both are brittle. A standard hss bit will work, but the point angle needs to be 150 degrees. Some of the newer twist bits have a negative cutting edge that prevents the point from walking, so a centre punch is not necessary.
3. I can buy a bunch of regular hss bits and throw them out after a couple of holes. (It is way too hard to sharpen very small bits correctly.) Plus I can re-sharpen the centre punch after every hole.
For now, until I can track down the proper hss bits, I will change regular bits after each hole or two, and maybe try and re-sharpen them. Ditto with the punch. Once I find a source for 150 degree pre-ground bits with negative cutting edges I will go that route.
If anyone knows of a source for the 150 degree negative edge bits let me know. (I need numbered bits, specifically #39.) Meanwhile, if you are drilling hacksaw or other hardened steel, be careful or you may ruin a half-finished pick as I did.