Tapping heat-treated steel

[AlphalphaPB]

Hi everyone. Knife customisation disaster story:

I'm trying to add my own G10 scales to a Camillus Arclite fixed blade knife. First off, I marked and punched a hole where I was going to be drilling, and the heat-treated blade squashed the tip of my punch. Then I snapped two carbide bits putting a hole in a heat-treated blade, before I finally figured out that I should go slooow. After that I tried to tap the hole, but I think the steel is harder than the tap. The thread things on the tap are getting squished.

Am I doing something completely stupid here? I was under the impression that the tap (which I bought from Knifekits.com) would be able to handle heat-treated steel, since it's sold to tap the Knifekits.com bolsters (which I believe are heat-treated).

I feel like an idiot for ruining a punch, two carbide bits, and a tap. Any tips?

[Ray Rogers]

You didn't say what size hole you're tapping but it doesn't matter much. The small taps are pretty sure to break and the bigger ones will break and/or jam into the blade.

Taps are hard but not usually any harder than a really hard blade. Taps, especially small ones, have to be able to flex a little so they are hardened to be tough rather than just plain hard.

Bottom line: it probably isn't going to work. If you must continue, at least use some tapping fluid and go very, very slowly backing the tap out after every quarter turn.

It would be a lot easier to drill some holes in the handle and just pin the scales on.....

[Chris Daigle]

Like Ray said, snug fitting pins and epoxy should be more than enough. The bolsters from the kits are meant to be drilled through if need be (300 series I think? :confused: ) The hardened blades are not.

Chris

[renhendude]

Actually you can drill through the hardened material , at least 58 rockwell o1 steel. You need what is called a M-7 bit with Chempakut heavy duty cutting oil.... go slow. You have to order 12 bits at a time but they work. These products are available at Advantage Drills Inc. outta Florida phone number 407-478-2487.

I hope this helps you out.
REN

[Geno]

A hard blade won't tap well period.
You could spot anneal the spots that need work and drill while red(pain), anneal and re-cook after doing work(hassle), or drill an oversized hole and use a threaded barrel that has the threads in it, or brass that can be drilled and tapped easily.Flare an insert and tap that instead.
MSC has threadded barrels(called electrical stand offs), 2-56 taps, anything you need to do the job.
Search MSCDIRECT
Or just use brass(say 1/4") and drill that(I use 2-56 threads), and tap, an easy solution.
Isn't that why you came here?
Go have fun, work safe, and be blessed.

[AlphalphaPB]

Thanks for the replies, everyone.

I've decided to try drilling and tapping a softer material fitted into a hole in the blade. If that doesn't work, I'll just pin and epoxy the whole shebang into place.