Here is an interesting problem

[DaveL]

I just did some 440C blanks and did think to check one more time but saw what I thought was the answer to my question. So, after initial heat treat, I removed the blanks from the foil and then found one blank was not drilled all the way through. The mark I used was a partial hole but not all the way. I had marked this blank with a 41 drill for two holes and a F drill for the other. The marks are there but not holes drilled all the way. When I looked the marks fooled me...

Now what...

[Doug Lester]

Get carbide bits in those sizes. They may be difficult to find locally but you could give www.carbideconnection.com a try. I'm considering it for those times that I austinize the tang by mistake an quench it. Another thing that you might try is to stick the blade into a can of wet sand to act as a heat sink and heat the tang with a torch to draw the temper more.

Doug Lester

[racinca]

I've never used 440C, but on all my carbon steel blades I draw the temper back to blue (spring temper) on the spine and tang. You can put it in a vise with a strip of copper on each side of the blade and heat the spine and tang with a torch. The thermal mass of the vise and copper will not allow the blade edge to overheat. You could also use wet sand as mentioned above for the same purpose. One caution, though - let it sit in the vise (or wet sand) until it cools down a bit. Otherwise as soon as you pull it out the temper will run down to the edge unless you can get it into water very quickly.
Tony

[Carey Quinn]

Since 440C is an air hardening steel, you will not get the tang to temper to a softer state as you can with a simple carbon steel.

You're just going to have to bite the bullet and buy some carbide bits.

Carey

[DaveL]

I have had a lot of great suggestions but did visit the carbide site and ordered a couple of carbide bits and they did the trick. I am very happy with that. Learn a little each day...