How do I make a hole in a hardened knife blade?

B

Badger

Joined
Mar 22, 2000
Messages
52
Don't ask me why I want to add a hole into a knife blade, I just like to tinker with things. I have an old Gerber LST with a high carbon stainless steel blade. The thought struck me that I should customize it by drilling a hole in the back edge near the scale, and adding a brass or steel thumbstud to it for one-handed opening. Anyway, my question is how do I make a hole in a hardened steel blade? What kind of drill bit, punch, grinder, or tool would I need to do this? Or is it just too much trouble to be worth doing. I have access to a full shop of tools and equipment, such as drill press, lathe, etc.

Badger

 
Get a solid carbide drill bit, crank your press up to full speed and use some good cutting fluid. Be sure to wear eye protection because carbide bits can fly into lots of little pieces.

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Badger,
You could probobly use a Carbide drill bit if the blade isn't too hard.

I used to anneal small spots on hardened blades using a steel dowel a little bigger than the hole you want to drill placed in a drill press.
I would press the dowel spinning at about 900 RPM ( faster is better)onto the spot were the hole was to go. the friction created enough heat to anneal that small spot.
all i did after that was drill the hole with a HSS drill bit.

Hope this helps

Eric
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Hi Badger
You are complicating things more than you need to. {Ask me how come I know that
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}
If you just want a good thumb stud buy one for $5.00 and install it with the included wrench.
If you get tired of it you can use the same tool to remove it.
And after removing it you have a really good shot at polishing off any sign it was ever there.
Just my opinion.
Dave Evans

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I have had similar experiences lately with drilling thong holes in steel like A2. I get in a hurry, and boom, the stuff work hardens and I ruin drill bits. Now that the stuff is work hardened in this area, how do I finish drilling the hole? And what cutting fluid should I be using?

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Danbo, soul brother of Rambo
 
Just a thought.... Has anyone ever tried using JB Weld to attach a little metal button for a thumb stud? I wonder if it would be strong enough to hold?
 
I once forgot to drill a thong hole in a blade before heat treat and as AT Barr suggested, a carbide spade bit with lots of Tap Magic or other fluid works well. I have used solid carbide bits but they are VERY brittle and will break if not careful. Use these only with a good drill press. The spade type bit is more forgiving.

You can forget about trying to use a high speed steel or cobalt drill bit, you can't get there from here.

As far as drilling hardened steel, carbide rules!

C Wilkins

[This message has been edited by C L Wilkins (edited 06-17-2000).]
 
I've heard of but haven't tried drilling with a dowel of some sort and loose abrasive. The hole won't be precise in size and it will be slow going, but it may be better than no hole.
 
In Alexander Weygers book, The Complete Modern Blacksmith, he recommends a trick using a cut off nail in the drill. You run it on the spot you want to drill until the spot turns peacock blue, indicating a relatively soft temper. Then you can drill the hole with an ordinary bit. I've never tried it myself. Has anyone else?
 
Badger, I drill RC-60 hardened ATS-34 all the time. I set the blade up for pins and then the customer changes his mind at the last minute and wants bolts, or the other way around. If you ever get to one of the wood working shows and see the demo of a guy drilling files, masonery blocks, tile, etc and also demo'ing a flexible grinding disk, stop and watch. I bought one of his drill sets after explaining to him exactly what I intended to use them for and getting his assurance they would work fine. And they do! I break one every now and then (or more correctly melt the carbide tip off the shank where it is brazed on) and he replaces it for free - no questions asked as long as I give him the old one back. Same for the grinding disk. I wore a couple out and he said I was running them too slowly in my cordless drill and to use them in a circular saw. But he still replaced them for free. I used the solid carbide drills for a while but found them terribly fragle. The least little bump as they break through will shatter them. I've had much better results with these other HSS bits with carbide tips and can also use them for general drilling.

Ron

 
Thanks to everyone for the replies. I'll try some of the suggestions, and let you know how it works out.

Badger
 
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