Dumb newby question!

[NCBoy]

I am in the middle of grinding my first knife. I am ready to heat treat but I had not drilled the pin holes. I have a cheap Harbor Freight drill press. I have ruined two drill bits and cannot drill through the 3/16 1095 steel. I was given the steel from another knife maker. Iis the drill press to weak or could the steel be hardened. I have cobalt heavy steel bits. Any ideas?

[Ray Rogers]

If the steel is annealed as it should be then a new cobalt drill should have no trouble drilling a hole in it. In fact, 1095 is normally very easy to drill. So, either what you have is not 1095 or it isn't in the correct annealed state (assuming your drills are not dull).

Even though this steel came from another knife maker it is still mystery steel to you and , I would guess, apparently to the other knife maker as well. Mystery steel is never a good idea for a beginner's first knife. I suggest putting this steel aside and buying some 1084 (or 1095 as a second choice) and starting over so that you know what you have ...

[ATalley]

Ray, thats great advice. its super important to know what your working with.

I've got two cents if anyone wants to read it... One possibility is that it was work-hardened. Meaning that the steel got too hot while you we're grinding and hardened it.

Cheap Drill press is probably not the issue, however if you we're drilling at a high rpm the drill bit could have gotten too hot and (again) work hardened the steel, causing the bit to break.

NCBoy, Take a look at the belt on the drill press and adjust it to the slowest speed. There should be a diagram on the inside of the lid with a schematic telling what pulley to place the belt on for what speed.

(Don't ask me how I know about work hardening. I'll just say it didn't end well, ha! My Dad always said I'd break an anvil with a rubber mallet)

I'm no machinist, but I've never been afraid to try.

Good Luck Sir

[NCBoy]

Thanks for your feedback. I ground the steel with bare hands. Is it possible to work hared the steel while holding it in bare hands?

[ATalley]

Probly not. Ray's right, it's far more likely it was harden before you got it, or its not what you though it was to begin with.

[Doug Lester]

Stick the blade into a can of wet sand as a heat sink and heat the handle with a torch. Get it to a nice deep blue and try to drill it again. Start with fresh sharp bits and keep your speed down as much as possible, 300 rpm if the drill has such a setting, which would be doubtful. The other thing that you can try is carbide bits.

Doug

[Fishbum2000]

Just a thought, are you oiling the drill bit while you're drilling?

[jmccustomknives]

Sounds like you are working with dull/cheap bits. Keep them sharp, use oil and don't let them get hot. I've been using a "cheap" drill press for 15 years, works just fine.
Here's a trick I have to use from time to time in a pinch when I can't seem to get a piece to anneal properly, a small concrete bit can get through. It's not pretty but it works.

[WBE]

The 1095 I got from Admiral steel was listed as annealed, but if it was, it was a typical common lamellar anneal, which forms carbon plates in the steel. Still rough on drill bits because of the extra carbon in hypereutectic steels. 1095 needs a spheroidized anneal. Try heating to a dull red and air cooling 3 or 4 times. That will often help.

[NCBoy]

Thanks for you suggestions. I do not have a torch and the bits were brand new. I did use oil. The bits were carbide new out of the package.

[NCBoy]

I have a gas forge and can heat the blade. Would you heat the entire blade?

[WynnKnives]

You could heat the entire blade and try to normalize it, after reading through I would say it's one of two possibilities that are VERY likely.

1.It's hardened, even if it's mystery steel new drill bits and a drill press should be able to go through it pretty easily. Unless it's some super steel. (Still doesn't negate the fact that you should always use a known steel so you know what your dealing with.)

2. Your running the drill press way to fast, like doug said steel should be drilled around 300rpm (or so), because even with soft steel and brand new bits you run the press at 1700 rpm or whatever the bits won't be able to do the job properly, get overheated and just burn up.

[cbsmith111]

You do need to make sure you're drilling at the right speed, but I doubt the slowest speed is best for the bit you are probably using. You can find a chart online that will tell you the speed you need depending on the material and bit size. If you try to drill too slow with a small but it will break. If you try to drill too fast with a large bit it will hang up or get too hot. Remember the larger the bit the more material it removes per rotation so the slower it needs to turn. A little cutting oil goes a long way too.

[Imakethings]

Regarding drill speed, set it at the lowest possible setting, go slow and use more oil than you need. Make a mess the first few times and slowly scale back the oil you use till you're getting it right.

Next up, annealing. Regardless of why it's hardened, the plain fact is that it needs to be annealed. Get yourself some vermiculite and a tray, box, or other non-flammable container you can fit the knife in. Fill it about 2/3 of the way up, gently heat the knife up to a nice medium or bright orange and bury in the vermiculite.
The vermiculite is a wonderful insulator, it will hold the heat and slowly cool the blade down taking it to an annealed state. If your blade is thin (and yours is) sandwich it between a couple of thicker pieces of steel and wrap em all up with wire to hold em together. The additional thermal mass in that sandwich will slow the cooling of the knife even further, I'd suggest 1/4 plates on either side. It should take it a good 1-2 hours or more to cool to room temp.

I also like the bonfire method, which is pretty much what it sounds like.

[NCBoy]

We found a solution. I heated the knife in my gas forge to 1500 degrees. Left the knife to cool inside the furnace. We sealed the forge with fire bricks and allowed it to cool to room temp. We then were able to drill the knife. Not easy but able to drill. Thanks for all your suggestions.