How to thread very short piece of pipe?

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Re: How to thread very short piece of pipe?

Post by Pontiacguy1 » Mon Mar 02, 2015 11:57 am

Saw a fixture a few years ago where a guy had a really great idea for holding these pieces and making a close nipple.

He made a fixture using a piece of steel bar stock. He drilled and tapped it on one end with a bolt larger than the pipe being held. This has to go nearly all the way through. You need to leave a section about the length of the diameter of your pipe that isn't threaded this way. He then drilled through and threaded the other end with the pipe thread that he needed.

So what happens is this: You drill out and thread one end of your pipe nipple. You then hand-tighten it into the piece you just made, and then put a bolt in and tighten it against the back side of the nipple, to keep it from screwing itself in any tighter while you thread the other side. You then chuck this in your lathe, and thread the other end of the nipple. When you remove it from the fixture, you loosen the big bolt and the pipe nipple should easily thread out. You also now have a fixture for making a bunch of them should you need it.

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Re: How to thread very short piece of pipe?

Post by Fred_V » Tue Mar 03, 2015 9:13 am

oooh, that's a nice idea.
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Re: How to thread very short piece of pipe?

Post by c.p.huntington » Sun Apr 12, 2015 2:27 am

Thank you for all your advice. What I end up doing was RET's suggestion of soldering the nipple
to another piece. I started by turning one end of a short piece of brass hex stock down
to where it would slip inside the pipe. The nipple was then placed on the turned down end of
the hex stock with the end that needed treading facing away from the hex stock piece. The two pieces
were then soldered together. The hex stock end was placed in the vice while a die was used to thread the
pipe end. The pieces were then reheated and pulled apart. I also ran a tap into the hole in the boiler
to enlarge the hole a little bit. After that everything went together without much trouble.

Earlier I had tried holding the nipple by screwing it into another piece of pipe and clamping
the larger piece of pipe in the vice. Unfortunately, by the time I had finished threading the
nipple it was so tightly wedged in the larger pipe that I couldn't remove it without damaging it.
I ruined two nipples this way.

I also tried holding the nipple on a easy out while I threaded it but the nipple kept slipping
and I wasn't able to do more than a couple turns with the die.

Thanks again for all the suggestions.

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Re: How to thread very short piece of pipe?

Post by Steven E. Kuhn » Mon Apr 13, 2015 11:27 am

If I were doing this I would do Pontiacguy1 suggestion. That is a great way to do it!!

Steve Kuhn

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Re: How to thread very short piece of pipe?

Post by Russ Hanscom » Mon Apr 13, 2015 8:09 pm

Pontiacguy1 has pretty well described how a commercial nipple chuck works

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Re: How to thread very short piece of pipe?

Post by KarlKobel » Sun Apr 19, 2015 4:20 pm

I stumbled on this method by accident.
I was machining a short pipe, but not making a nipple, and thought of using the die in the three jaw chuck as a quick holder.
It worked so good, and not wanting to abuse my die, I tapped a short piece of round stock and slit the end in three places (like a collet). Narrow the diameter on the solid side of the slits.
The three jaw chuck collapses the 'collet' and holds the previously threaded pipe while threading the other end.


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Re: How to thread very short piece of pipe?

Post by blff cty lcmtv wrks » Wed Apr 22, 2015 11:19 am

give this a try. make a nut out of a piece of hex. the size is left up to you. i use 3-8" or 7-16", for the bigger size nipple. i assume we are talking about the mtp stuff. thread it with the pipe tap that you are using at the moment. now take that nut and stand it on it's end and with your power band saw, saw through one side of the nut, thereby turning it into a threaded split collar. thread the nipple into it and then clamp the whole works into a three jaw chuck, leaving the unthreaded end hanging out. you might have to clamp the daylights out of it. proceed to thread. when you remove split nut, collar, or what ever it is called now, the nipple should be loose enough to turn out without too much effort. it works for me, however as usual, there are no gaurantees expressed or implied.

big c

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