Anyone using v groove style bits on alum?

Good day.

I am looking to make threads on an alum round pipe on my rotary.
I think I need to use v groove style bit to accomplish this.

Any on done this before on a rotary? Is this the style of bit I am looking for?or something else?
In the end should look something like this ANWUYANG Stainless Steel Full Thread Nipple Barrel Pipe Fitting, 1/4" 3/8" 1-1/4" 1-1/2" 1/2" 3/4" 2-1/2" 2" 1" 50/75/100mm Long Hollow Dental Tube, 1pcs (Color : 2" L=50mm) : Industrial & Scientific

No specific tread pitch needed.

Thank you!

How long? Because I do this all the time and I don’t use rotary axis;

This guy will walk you through the basics;

Pipe would be 2.5" diameter and 10" in length.


The thread profiles are very, very specific. The bit you would need to use would have to have the profile for the specific thread you are cutting.

Like if you are cutting ANSI Trapezoidal vs BSPT tapered vs NPT vs… you get the point. You’ve got like 30 of them and each is very different.

Probably easier to get a die and cut it manually.

Did these threads on the 4th in blk walnut, I used the spiral gadget ifI remember right then a 60 deg cutter for the internals

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for the most part, well let me say I’ve cut a lot of threads on the lathe and it seemed like 60 deg came up a lot cutter wize…

That looks spectacular. I’ve cut countless threads in steel/aluminum/nylon, etc on the lathe and mill over the years and never would I have considered doing it on the 4’th. Not that the idea didn’t cross my mind, I apparently just dismissed it a little to fast. @Bstanga , thank you for sharing those pictures!

i can send you the aspire file if you to have a look?

6 tpi test.crv3d (586 KB)
4 tpi.crv3d (588 KB)
20 inch 1.5 threaded blk wlnut.crv3d (560.5 KB)
here are a few file from testing threads on the 4th

All the threads I cut have to be a certain spec. Usually for AN screws. I think the longest outside I have done on the AvidCNC was 50.8 mm or there abouts. Same for internal threads. So when people talk about threading I never have control of what is either being threaded into or onto the what I am machining.

That tut from the NYCNC guy is actually pretty good. John Saunders drives me nuts sometimes but he does have content for the new folks that is valuable.

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@Bstanga , thank you for sharing thouse, I’ll check them out. The two larger threads I end up working with commonly are 1.5in-4tpi and 2in-4tpi. Both of those are ACME, although 2In-12 UNF and 1&1/2-12 UNF both pop up from time to time. I’ve got a set up taps and dies that run up to 2in for both UNF and UNc, but only a handful of bigger ones that are mostly for pipe threads. IE 2&1/2-11 NPT for both tap and die sets…

Below is an example of a 20-in long section of 1&1/2-4 ACME that I turn on the lathe pretty regularly. I had ruled out the idea of spending an afternoon on a D-Bit grinder to make a cutter and going at it on the 4’th axis, but you’ve got me thinking about this…

I usually helically interpolate the female thread for the nut over on the mill. The two images, below sho the startings of one o these.

Of course this is a reasonably specialized application and I send both of these out for hard anodize. The aluminum piece I am threading has a 3/4in through-hole in the extrustion, but the stock has a reasonable number of stresses that the follow-on rest on the lathe helps with. I “may” have to make something like that for the 4’th axis setup, but I can see where cutting this with a spindle and a custom cutter in 2-passes, could save tons of time over doing it on the lathe since I run this pick-up job for a friend a few times each year and usually end up making 5~10 each time. I made the first set of these for myself personally and my frined has gone on to produce and sell quite a few of them in the years since. The hollow extrusion allows for the passage of wires through the screw joint in a protected / constant length manner so the cable assembliess don’t flex.

Thank you for the input. If this turns into anything I’ll definiely post back here and share.

Wow that looks great, the whole time I was reading I was thinking what could a AL lead screw be used for? I’m glad you explained, wires through the center. Back to the 4th you could make a follow rest attached to the linear rails that could be very precise

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Good day I am looking to cut something similar to the attached pic.
on the rotary. any recommendation on the bits?

use 60 deg vbit take .005 cuts to start and listen to the

machine and increase from there