Announcement

Announcement Module
Collapse
No announcement yet.

non-standard TPI pipe threading

Page Title Module
Move Remove Collapse
X
Conversation Detail Module
Collapse
  • Filter
  • Time
  • Show
Clear All
new posts

  • non-standard TPI pipe threading

    I'm fixing up a Jeep CJ7, and I'm making a custom EGR tube since the one I had broke and the stock one might not fit between some of the parts I have now anyways.
    The threading appears to be not-very-standard. It's about 16 or 18 TPI (I'm leaning towards 18), and the tap is about 3/4" wide.
    I've never used a threader before, but it seems pretty straight forward. My question is what parts would I need to make a 16 or 18 TPI thread on a 3/4" pipe. It appears to me I'd need a drive (probably the 600 would be my choice), and the right 11R die head, but I don't see much information on what TPI each has.
    Any help would be appreciated.
    -Ron

  • #2
    3/4" pipe threads are 14 per inch. Are you sure it is even pipe threads on the tube. Is the threaded end tapered or straight? 3/4" bolt threads are 16TPI for fine thread and 5/8" bolt uses 18TPI for fine thread. Another thought would be to reuse the original pipe ends and weld new tubing between them
    info for all: http://www.hoistman.com http://www.freeyabb.com/phpbb/index....wwtoolinfoforu --- "I like long walks, especially when they are taken by people who annoy me."

    Comment


    • #3
      I've been finding more information around the web, and I think I'll go with a manual threader (mostly for safety and price), and I'll check tonight whether it appears to be tapered (it didn't look like it, but I could be mistaken).

      The tube I'm replacing is very odd and can't be used again, since one half of it is heat welded into the exhaust manifold that I'm tossing, and the setup is kinda odd (loose threaded piece pushing down a flanged tube).

      I think I'll make a few more measurements tonight and possible get the 00RB die head that will do 16TPI for 3/4" or the one for 18TPI at 5/8".

      Comment


      • #4
        Stop by a hardware store and pick up a 5/8" and 3/4" fine thread bolt. Try them and see if one of them fit. If the original was not tapered it is not pipe threads
        info for all: http://www.hoistman.com http://www.freeyabb.com/phpbb/index....wwtoolinfoforu --- "I like long walks, especially when they are taken by people who annoy me."

        Comment


        • #5
          I've not worked on any Jeep products, but an increasing amount of automotive equipment is built to metric specs. Is that a possibility?

          Metric threads are specified in thread pitch rather than TPI, e.g. 1.5 mm between threads. Thread form for metric is enough different that even if the pitch and TPI are equivalent, they still are not interchangable.
          Dick

          Comment


          • #6
            The Jeep CJs were standard. I had a 79 for quite a few years with a 304 engine.
            info for all: http://www.hoistman.com http://www.freeyabb.com/phpbb/index....wwtoolinfoforu --- "I like long walks, especially when they are taken by people who annoy me."

            Comment

            Working...
            X