Hello, I have some Ridgid Pipe Taps for sale on ebay. Potential buyer asked if they could be used for black iron pipe, and for galvanized pipe. All are NPT sizes, I am guessing the answer would be yes, but I need to be sure. Any help? Thanks, Lou

Yes, you should be able to use them on both types of pipe without a problem.  (assumes user lubes, cleans, backs off, etc.)

Hello, p_toad. Thanks for the confirmation!!!!!!!!  Regards, Lou

I need a 1 inch pipe tap. I need a good American high speed steel one. That would be a 1-11-1/2 inch NPT. I work on small gas engines and need to clean of the threads on the exhaust port outlet sometimes.

EvilDr235

Quote from: EVILDR235 on March 01, 2018, 08:59:21 PM
I need a 1 inch pipe tap. I need a good American high speed steel one. That would be a 1-11-1/2 inch NPT. I work on small gas engines and need to clean of the threads on the exhaust port outlet sometimes.

EvilDr235

I would use a chaser.  I'd use a die for threading bare pipe. 

Chilly

Hello, Chilly. I use a Craftsman Re-Threading Die Set  for cleaning up small bolts/studs, 1/4-20 thru 1/2- 13. Anything bigger than that I use whatever bolt dies I have here. I use taps for internal thread chasers when needed. Whenever I remodel the occasional bathroom or kitchen, I always run into the troublesome TEE in the wall, usually galvanized, and I clean up the rusty/slimy internal threads with a pipe tap. My question is, are there dedicated internal thread chasers, for bolt & pipe sizes? Thanks, Lou

Quote from: lptools on March 02, 2018, 04:07:48 PM
Hello, Chilly. ...... My question is, are there dedicated internal thread chasers, for bolt & pipe sizes? Thanks, Lou

Inquiring minds want to know.

you might want to check places like
http://www.victornet.com/
or
https://www.zoro.com/

I have no direct association with them except good service on my orders.

in bolt hole, I use a bottoming tap.

The question is if there is 'chaser' for NPT holes.

 sorry leg17, I saw your request for bolt & pipe.


  MSC has listings for pipe thread chasers.

  google MSC  and check for pipe thread chasers.

Quote from: lptools on March 02, 2018, 04:07:48 PM
Hello, Chilly. I use a Craftsman Re-Threading Die Set  for cleaning up small bolts/studs, 1/4-20 thru 1/2- 13. Anything bigger than that I use whatever bolt dies I have here. I use taps for internal thread chasers when needed. Whenever I remodel the occasional bathroom or kitchen, I always run into the troublesome TEE in the wall, usually galvanized, and I clean up the rusty/slimy internal threads with a pipe tap. My question is, are there dedicated internal thread chasers, for bolt & pipe sizes? Thanks, Lou

Sorry for the late reply.  The easy answer is yes, there are pipe taps in all sizes.

The harder thing is finding sizes much larger than 1/2" or 3/4".

In fire sprinklers the smallest steel pipe we use is 1", and we thread 1"-2" regularly. Most every building has at least one 2-1/2", 4", or larger thread at the FDC.

We dont tap much. I have up to 1" pipe tap handy, and I thinkmi have av1-1/4" and 1-1/2" somewhere.

For re-cutting old threaded fittings I think I would try making a tap.  Take a pipe nipple and file some v shaped grooves in the threads and perpindicular to the threads. Drill a 1/2" hole a few inches from the pipe end to put a rod through. Harden the pipe as much as you can. I would think that a schedule 80 (maybe aseamless A106) would do the job.

I'll draw what I'm talking about and post it.

Chilly

Quote from: turnnut on March 03, 2018, 08:19:07 AM
sorry leg17, I saw your request for bolt & pipe.

  google MSC  and check for pipe thread chasers.

I googled.
All they list are chasers for pipe OD threads.
Were you able to find 'chasers' for internal NPT holes like the OP was looking for?
All I have ever used or seen used are normal pipe taps.

leg17,  I should have read it through the 1st time,  I just went back and checked, did not find chasers for ID, but their ID taps are flat bottom like a bottoming tap.

I see no problem chasing threads with these.  I have used them on cleaning old elbows.

In a past life i did a lot of steel pipework manifolds that were manufactured to fit then Galvanised. All threaded outlets on the manifolds had to have the threads re-cut to remove the Zinc build up from the galvanising process. Hence the collection of BSP taps 1/8" to 2". The threads were easier to clean out if they were heated gently before the tap was run in & out of the fitting several times.