Frizzen Pivot Hole

What's going on here? I bought a replacement frizzen casting for my R .E. Davis Jaeger lock. I don't think it was heat treated because I filed it and cleaned it up easy enough. When I went to drill the pivot hole I got half way through and it started smoking and quit cutting. I have tried coming in from the other side with a smaller bit and cutting oil. I have now gone through four bits. I did punch through but I still don't have it full size all the way through. The part has turned blue around the hole. I appears to be harder than Chinese arithmetic. Can't remember where I heard that. Anyhow, did I work harden it? If so, what can I do to soften it, so I can drill through it? :cursing:

 

[Stophel]

This is something I often find with Siler sears and tumblers made of that horrible, horrible O1 steel. Sometimes, they can be very difficult to anneal. Heat the part to dull red. Just to make sure, bury it in ashes or something (I have a bag of garden lime handy. This works fine) so that it cools as slowly as possible. Resharpen your bits and HOPEFULLY, you will be able to drill it then. Now, I habitually anneal ALL siler tumblers and sears before working on them in an effort to avoid this.

While I would not be surprised to hear this problem in O1 steel, I actually am surprised to hear it about a frizzen, which are all ostensibly made of 1095, normally a very trouble-free steel.

 

[hootal]

When this happens to me, it's due to the bit getting dull. Generally if the lock is a kit, none of the parts are even hardened yet. Bits always seem to go bad at the worst time.

 

[LRB]

I find it best to use cobalt drill bits on 1095, and if the hole needs precision placement, I use a new bit if I have one. 01 will air harden to a brittle degree if ever heated to a near red or above. Especially with small pieces, and is very difficult to completely anneal without a long oven treatment. It is very possible that 1095 is somewhat the same, but not quite as bad. The casting may have cooled to fast when removed from the mold. I have recieved bars of 1095, which were supposed to be hot rolled and annealled, but would destroy cobalt bits.

 

[Zonie]

Unfortunatly you have discovered "work hardening".

A hardenable steel can work harden if the drill bit becomes slightly dull or if it is left to "dwell" without being fed into the material for even an instant.

As the others have mentioned, the only solution is to anneal the part to get it back to a soft condition. The key to annealing these materials is to cool them as slowly as possible from a red heat.
I have had some success on a small part with a propane torch but it takes time.

I've known folks to build a charcoal fire and put the part in it to get it up to a red heat and then slowly let the coals die down but this is risky.
If it is held at a bright red heat too long, it can remove the carbon from the surface of the part. Without carbon in the steels surface, it won't harden properly. If this happens, a frizzen won't throw sparks without recarburizing it with something like Kasenit.

If it were mine, I would try the propane torch method directed only at the area where the hole goes thru the part. It might take a half hour sloooooly cooling the part to get it down to 500-700 degrees. At that temperature, you can let it air cool to room temperature.
Then buy the best Cobalt High Speed drill bit you can find and redrill the hole.
Remember, constant feed is required on the drill bit or it will work harden again.

 

[mikelange]

The bit got dull and overheated. Running it too fast might have played a part, too (not saying you did; just that it might have). Annealing the part might work. You could try a cobalt bit. A solution I've found, when all else fails, is to use a pointed diamond bit in a dremel tool, and by using the edge of the tip as much as you can (without enlarging the hole beyond usable bounds) cut through from the undrilled side. Be careful, but this will work if it's done right.