Very confused

[Stacy E. Apelt - Bladesmith]

I especially like three flute carbide bits. They seem to make holes in tangs effortlessly without breaking as easy as the two flute bits. I have four flute bits for some really tricky drilling tasks.

I suspect the difference in this blade is that you are getting better at HT. A hardened and tempered blade is too hard to drill with normal drill bits - it should be drilled with carbide. If you were drilling it easily with regular HSS bits before, your HT wasn't very good.

 

[Don Hanson III]

^This... I always follow a set procedure for every knife that I make. First step is design, then profile, then drilling the holes in the handle. When you follow a set plan, things usually are easier. When you fail to prepare, then you prepare to fail.

Also, I'm surprised nobody commented on how the OP previously drilled through "hardened" steel so easily but has problems now even though he did the same as before. Makes me wonder how successfully hardened the previous ones turned out or whether everything was actually done the same way. Doing the exact same thing should yield the exact same results if the steel was the same batch.

Yes, I would be concerned with previously heat treated blades.

 

[Tenebr0s]

Suspend the blade in a bucket of water or wrap in wet paper towels (or clamp between heat sinks like two thick pieces of aluminum, copper, etc) . Heat the tang to a dull red (sub critical temperature) and let it cool to black. Repeat this a couple times. The tang should now drill like butter.

 

[weo]

Suspend the blade in a bucket of water or wrap in wet paper towels (or clamp between heat sinks like two thick pieces of aluminum, copper, etc) . Heat the tang to a dull red (sub critical temperature) and let it cool to black. Repeat this a couple times. The tang should now drill like butter.

An induction forge works really well for this.