And Yet Even More Tapping Problems

I ran across a similar problem to the guy with the aluminum the other day. During my lathe experiments to make a pivot pin for my knife I discovered I didn't have any stainless nuts the right size for my pin. No big deal I thought. I'll just make one. I drilled out a piece of the same stainless bolt I used to make the pivot pin and then tried to tap it. Holy cow. Talk about tight. Never could get all the way down to the free spin section on the tap. I did get far enough to get it on my pin, but it started me thinking. Is there a best way to drill work hardening materials to minimize hardening so you can tap it easily?

There are a bunch of little tools and fixtures I have in my gonna build it when I need it plans that will require drilling and tapping as part of the assembly.

Reply to
Bob La Londe
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Very sharp drills, feed it hard, about 20-30 SFPM for HSS drills, heavy oil.

Reply to
Steve Walker

Yes, and now try to take that nut off! A rule of thumb is to never use a nut of the same stainless material as the bolt. If you HAVE to, use the nickel bearing Never-Seize. The problem is galling. Big Time!

Pete Stanaitis


Bob La L> I ran across a similar problem to the guy with the aluminum the other

Reply to

NO. I want it to stay on. The original pin was just peened over like a rivet.

I wish. It went on a little too easy. After cutting my pin smooth with the nut I put a couple detents in the nut right along where it meets the pin just to make sure it never comes off. Looks almost like a solid end with decorative detents on it. In this case a very desirable affect.

The last thing I want is the blade bolt coming out in my pocket. LOL.

Reply to
Bob La Londe

When tapping stainless, use the next size larger drill. Threads will still hold quite well, and you will avoid the scars from broken taps.


Reply to

NOW ya tell me. Too late, of course. This thread would have saved me several taps this summer trying to tap stainless to add fittings...

But now I know!

Reply to

Sometimes it can't be helped. Years ago I worked on some high vacuum gear. All stainless fasteners. The easy fix is a small drop of some kind of lubricant. All I had was some vacuum grease, but it worked fine.

Reply to
Jim Stewart

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