Tapping Pipe Fittings

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John_S
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Re: Tapping Pipe Fittings

Post by John_S » Wed Dec 20, 2017 8:28 pm

Bill Shields wrote: the bad thing about all of this is you generally need two taps....one to get started and one, with the end ground off, so that you can work blind holes - or 90 or 45 ells.
My drawer of taps and dies agrees with this statement! I have two of all the MTP taps and a handful of the smaller (1/8 and 1/4) taps just as Bill describes.

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Fred_V
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Re: Tapping Pipe Fittings

Post by Fred_V » Thu Dec 21, 2017 8:33 am

What do you guys use for brass tapping in 1/8" to 3/8"? The catalogs always say "not for tapping brass".
Fred V
Fred V
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rkcarguy
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Re: Tapping Pipe Fittings

Post by rkcarguy » Wed Dec 27, 2017 4:38 pm

Fred, I know in my turret lathe operation days, we used to use old, more dull pipe taps in brass and bronze. What happened is the stuff cut so easy that a new sharp pipe tap would get partially to depth where the tap is starting to cut fully into the metal, and it would just cut all the treads out instead of continuing deeper, leaving you a worthless tapered hole. So our shop had to have 3 of each size, regular sharp, regular dull, and a "bottoming" version for blind holes as stated above. Toss in the fact that we did 1/8"-1" NPT, and this was some serious $$$$ in taps!

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apm
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Re: Tapping Pipe Fittings

Post by apm » Sun Jan 09, 2022 9:35 pm

I am digging up an old thread here, but I was looking to do some plumbing of a few lines and got sticker shock when seeing what PM Research sells a tap/die for model pipe taper. A quick trip to a british website https://www.tracytools.com/taps-and-die ... -40-tpi-me and the prices become much more affordable for model engineering taps. So then the question is do the model engineering taps self seal and do they work on plumbing lines? What would the Brits use for 3/16", 1/4" lines? Since I am tapping my own fittings and tube I don't see anything wrong with using British dies if needed.

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Bill Shields
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Re: Tapping Pipe Fittings

Post by Bill Shields » Sun Jan 09, 2022 10:20 pm

Sealant is pretty much needed on everything unless you have a crush copper or aluminum washer involved..

Whatever threads you decide to use be consistent on the loco
Too many things going on to bother listing them.

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Fred_V
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Re: Tapping Pipe Fittings

Post by Fred_V » Mon Jan 10, 2022 8:26 am

Model engineer taps are not tapered so as Bill says use a sealer and hope for the best. Those type taps are available here too just google your tap size and order. I've gotten them from Amazon. search also for model taper pipe sizes.
Fred V
Pensacola, Fl.

AnthonyDuarte
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Re: Tapping Pipe Fittings

Post by AnthonyDuarte » Mon Jan 10, 2022 11:32 am

If you want tapered model pipe threads you could also try Godshall's Custom Machining:
https://godshallscustommachining.com/pr ... ipe-thread

As mentioned, the tools on the link you shared are not tapered threads.
I'd personally recommend always using something to seal threads even if they are self sealing.

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Dick_Morris
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Re: Tapping Pipe Fittings

Post by Dick_Morris » Mon Jan 10, 2022 6:41 pm

Although the MTP taps are expensive, if used carefully they will last a long time. In relatively light use mine from Cole's are at least 40 years old. You can probably save some money on the largest MTP size by buying 1/16" pipe taps and dies. They are the same thing under a different name.

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NP317
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Re: Tapping Pipe Fittings

Post by NP317 » Mon Jan 10, 2022 10:02 pm

Dick_Morris wrote:
Mon Jan 10, 2022 6:41 pm
Although the MTP taps are expensive, if used carefully they will last a long time. In relatively light use mine from Cole's are at least 40 years old. You can probably save some money on the largest MTP size by buying 1/16" pipe taps and dies. They are the same thing under a different name.
What Dick said. Same story for me.
RussN

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Dave_Johnson
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Re: Tapping Pipe Fittings

Post by Dave_Johnson » Mon Jan 10, 2022 10:20 pm

If you are going to be doing any amount of piping work now or in the future, you might as well get the taps and dies.

For me, probably 90% of my pipe work that is threaded is 1/4 inch. That is for both 1 inch scale and 1.5 in scale.

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Fred_V
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Re: Tapping Pipe Fittings

Post by Fred_V » Tue Jan 11, 2022 8:13 am

You don't have to buy the whole set, just get the 2 sizes you need now and add to it later.
Fred V
Pensacola, Fl.

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