Made a threading tool out of a large tap to thread a hex nut. My internal threading tooling is pretty lame so after going through my drawers I came up with the idea for this tool. I just ground off all the teeth except the first one and then mounted it on a QC boring bar holder. Did a passable job. Thought I'd pass this on to the other lathe owners out there.
Internal lathe threading
- Thread starter Yooper
- Start date
Resouceful!
I might have left all the teeth on the flute, and taper ground the first four to give a progressive cut.
North Idaho Wolfman
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Lil Foot
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Nice! When teaching new machinists, one of the hardest things to convince them was that there are no hard & fast "one way only" rules. Got to think out of the box occasionally.
Somehow I thought the threads looked "mighty close". Just different diameters.
Must be the camera angle ;-)
Practically, I keep a selection of internal threading tools on hand. Biggest headache is swapping tools between QC tool holders. Three lathes, three different size QC tool posts, and it always seems the last time the desired threading tool was used, it was on one of the other machines. ;-)
My one and only south bend is almost as rigid as a wet noodle,so any advantage for threading is a bonus. I had a collection of old taps given to me,so experimenting with them wont seem so wasteful.
I'm wondering how much difference in thread pitch would be a problem due to the helix angle on the tap. Just asking.
That is an issue with this method. You could grind some of the tooth under the cutting edge to help a bit. This is just to get you out of a jam like I was in.
Would still like to hear from some of you fellow lathe owners what you like to use for single point internal threading.