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Discuss Dodgy shower arm thread? in the Bathrooms, Showers and Wetrooms area at

  1. DodgyDIY

    DodgyDIY New Member

    Hello plumbing pros!

    I'm nearly done with my bathroom refurb, but got a problem fitting a shower arm I bought from

    In the attached pic, the chrome thread is the one that screws into the wall. The brass thread is for a handheld shower fitting from the same set (for comparison).

    I can only get the shower arm thread to go about 1/2 turn into the backplate elbow. You can see the shower arm thread is flatter, unlike the sharp brass one you would typically see.
    The brass thread screws in beautifully.
    To my untrained eye these all appear to be BSP(P). So the logical answer to me is that the chrome thread is not cut properly. I asked to investigate and they sent me an identical replacement.

    What do you think guys, am I missing something? Or is the shower arm not fit for purpose?

  2. ShaunCorbs

    ShaunCorbs Trusted Plumber GSR Top Contributor!!

    I would say yes, all the ones I've fitted / seen are like a stnd tail

    Looks like it's been missed off final threading
    • Like Like x 1
  3. rpm

    rpm Trusted Plumber Top Contributor!!

    Not exactly scientific, but measuring the TPI on the screen they are different.
    • Like Like x 1
  4. rpm

    rpm Trusted Plumber Top Contributor!!

    One might be BSP thread the other is a machined thread would look for another component that's takes the machine threaded part.
    • Like Like x 1
  5. Phil

    Phil Plumber

    Looks more like the thread on my dumbell bar!

    Come on give us half a chance, these are hard enough as it is to fit.
    • Like Like x 2
  6. DodgyDIY

    DodgyDIY New Member

    Thanks for the replies Gents, much appreciated.
    I too thought it looks like a thread that doesn't belong in plumbing, so have asked for a refund while i look for a better quality alternative. Triton do a similar one.

    I shall look forward to fitting the sink, toilet and bath next! o_O
  7. ShaunCorbs

    ShaunCorbs Trusted Plumber GSR Top Contributor!!

    You know where we are if you get stuck :)
    • Like Like x 2
  8. Chuck

    Chuck Top Contributor!!

    It looks to me as though the chrome thread is an American 1/2" UNC thread, which is 13 TPI. 1/2" BSP and its relatives are 14 TPI.
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