saw mill blades

[J CARPY]

I have been cutting out blades out of saw mill blades, and grinding to shape, and drilling holes in the tang. I am using good cobalt bits, and having one heck of a time drilling through the tang. I do not have a forge, or a kiln as of yet (after new year) so just getting ready. Assuming I have to heat treat, and aneal. Will I be better off waitng till I aneal to drill holes?
This stuff is really hard. Or if I drill holes, is there a need to aneal? I am using a 6x48 grinding belt with 80 grit to shape as far as I know it grinds OK. But this one and one more will be two.

[srtben]

depending on how thick they are you can at least soften the tang with a propane torch, (bernzomatic style works well). Heat it up to at least a dull red, and let it cool down as slowly as possible. you can try sticking it in ash or between a couple fire bricks. That should help save some drill bits, I would also recommend using cutting fluid for drilling it helps keep your bit from scorching.
Hope this helps!

[J CARPY]

I use drill ease, and graduate my drill size as I go up, I also drill slow, and stop Part way through to give time to cool. When I drill there are metal flakes, no shaving? I can see the cutting fluid heating as I dril. I am still assuming that I need to heat treat? How can I tell? It is thicker than 1/8. As I grind it sparkles, not spark.

[Bobby Urban]

If you have it clamped on a drill press you can heat while you are drilling or heat the spot and drill as it cools.

[beetlebailey1977]

I would not heat then drill it, you want it to stay cool while you drill it.  I suggest to anneal the tang first.  SRTBEN was correct.  Heat to dull red then cool as slow as possible.  Putting it in lime works very well.  Will take a while to cool.

[Ragnarok Forge]

Clean the surface of the tang until it is bare metal.  Clamp a vise grip between the blade and the tang. Put the blade section in water and heat the tang with a propane torch.  I run the torch until the steel runs thru the color spectrum to a light blue.  I then let the tang cool to air temp keeping the blade in the water.  This softens the tnag enough to allow drilling without ruining the drill bit.  Just go slow with the drilling and use lots of oil

[sticshooter]

If you go real slow witha cobalt bit you should be able to poke a few holes. BUT it is better to anneal if you can<><

[Kevin Evans]

I agree with Lowell only I would do it three times ,cleaning in between so I could see colors change.

[ermont]

Definitely heat it and use Lime or sand to anneal the tang.

[J CARPY]

Thanks!
Lowell
I tried your Idea this weekend, I clamped vise grip between blade, and tang, and put blade in water. I heated the tang with my bernzo-matic torch until blue. Then let it cool to room temp. I could not drill it, so I tried it again, with a little more heat. Not sure about the colors. But when it cooled I could drill easily. I hope I did not ruin my blade, (oh well good learning experiance) I have a little blue on blade when the knife cooled, and after It cooled the tang was a dark grey. It sanded off very easy down to original color. I will heat treat when I get a forge, or kiln.
Any input?
Thanks again learning is fun!