Threading pipe

[cey146]

I bought a Rigid 700 pony at an auction, and bought a set of 12R dies off of Ebay. All are in good physical condition, and appearance. The problem I have is when threading pipe with any of the dies that I've tried, (1/2, 3/4, 1, and 2") they start out cutting good clean threads, then just start chewing their way through. This occurs at about the time the threader has cut 4 good threads. Has anyone had a similar experience, and if so, how did you correct it?
Thanks.

[BHD]

they may be dull, and it may be crap pipe,

[cey146]

The thread cutters have no sign of cracked or damaged teeth. I thought the same of the pipe, and have tried several different types. No change...

[Mightyservant]

Generally it's not going to be a problem with your dies or power head if they are in good working order. Most of the time it due to the pipe quality.

But poor threads happen to us all the time since we do hundreds of field threads in a year. It's just part of the job.

We increase the odds of a good outcome by using quality pipe wether its domestic or imported. We use dark cutting oils with a higher sulphur content like Oaty Hercules or Ridgid dark. We keep plenty of oil flowing through the cutting process. We try to keep dirt, sand and water out of the oil. Use a wheel cutter to cut the pipe. From time to time we disassemble the die head and clean it thoroughly. We use small wire brushes to clean the chips off smaller ratcheting style dieheads.

Your already using decent (Ridgid) dies so it's probably not going help to replace them. Try threading brass pipe and see how well it performs. If your still getting poor quality threads it might indicate a worn diehead.

Be forewarned, sometimes when your threading pipe nothing seems to work and you feel like your in the 7th ring of hell. So before you throw out your equipment, rent a threader to see if it'll do any better than your own.

[toolaholic]

R U Using threading oil ?

[PLUMBER RICK]

Buy some factory nipples and adjust the die to those threads make sure they are in the proper order 1,2,3,4.

Rick..

[cey146]

Yes, bought a new Rigid cutting oil dispenser, and the oil.
I tried to adjust the teeth by loosening the grip plate, and it only tightens back up in the same place. Even tried with it somewhat loose. I will check again on the orientation of the die cutters, but fairly certain I have them in the correct 1,2,3,4 sequence.
I threaded rigid metal conduit for a living for nearly 20 years, and never ran into this..... except when the cutting teeth were shot.
Thanks for the responses.

[Mightyservant]

I believe rigid conduit is a softer alloy, a loose plate will exacerbate threading problems. Since you know how to thread pipe you've got a pretty good idea what to expect.

Sometimes very fine dust like metal gets behind the dies within the diehead overtime and changes the geometry up just enough to foul things up.

We run into this very often with steel pipe but very seldom with brass pipe. Steel pipe is not what is used to be however our high speed threaders rarely have poor threads. That little comfort when making field threads.