spot softening ?

Is there any way of softening just one small spot on a blade? The knife I am making has already been heat treated and had the guard installed and I would really prefer not to have to remove the guard but I need to drill a couple of pin holes (dumb mistake).
Thanks
Steve
Oh I am using 440C 3/32 thick and I need to drill some 5/64 holes.

Although spot annealing is possible (I've never done it), I would recommend using a carbide drill bit.

You don't say where the holes need to be drilled so I will assume you need the holes in the tang for attaching the handle slabs.

You can use an oxy/acetelene torch or propane/mapp and oxygen torch (anything with a hot flame that is small) to heat the area of the tang needing drilled. I would wrap the blade in a wet cloth to be sure it stays cool. Heat the steel to a dull gray color and let cool slowly. This should do the trick for you.

Some people would consider heating the entire tang, your option.

Good Luck.

440C is an air hardening steel and I don,t think spot annealing is going to do the job. Like Don says, Try a carbide bit. Bob please correct me if I am mistaken,I just haven,t had any luck spot annealing stainless steel.

Roland

440C is air hardening. I have spot anealed it by getting it hot and forcing it to cool very slowly. Sometime you still get hard spots but I have been abole to drill it out. Not saying it is easy but it is possible.

You could try a masonary drill bit available at most hardware stores,they don,t drill a a perfect hole ,and don, t last long but are cheap,but you won,t have to wait while you special order a carbide bit.drill at a low speed and use a steady pressure with lubricant..Hope this helps...

Soak a thick piece of felt in water [put some weight on it to hold it under water] for a couple hours, then into the freezer for a couple more.

Tape the felt as close as possible to the part you don't want to anneal. Turn the blade so the spot you want to drill is up and the felt down in a vise [usually point down].

Get the spot up to cherry red [I use a small propane torch from the hardware store], then stuff the whole thing in a deep bucket of ashes and leave it for at least an hour to cool and soften.

Use a glass-drilling bit [Home Depot, Lowes] and go slow with lots of Cool Tool. These bits will usualy break just at the end of the hole when they catch on the exit side- so drill almost through and then switch to a bit you don't like for the final piercing. Repeat the whole thing for the next hole.

There are probably a zillion ways to do this, and they all may work. This usualy works for me. And doing all this to drill a simple hole helps me remember not to harden until the drilling is done.Good luck-
Dave

Buy a reasonable qualite masonary bit in the size you want. Sears, Task, Black & Decker, Joran all purpose drill bits will all work ( Vermont has never worked for me). These bits will drill oversize holes- drill slowest speed and use cutting fluid of some kind. Believe i or not S.T.P. engine additive will work well. When placing your pins put one up against one end and one against the other hold end and you will get the job done nicely. Regards Frank.