Identify this bolt ?

Wig
Wig Posts: 14,139 Forumite
edited 4 January 2020 at 2:00PM in Techie Stuff
I don't have a thread gauge, I have used my eye
I do have a micrometer

threads are 11.65mm diameter (0.458")
pitch I got 35/21 = 1.6666mm 30/18 = 1.6666mm (15+ tpi)

What is this bolt size please ?

Comments

  • The nearest I could find in my books is a 7/16 UNC.
    That has an outside diameter of 11.12mm and 14 TPI
  • molerat
    molerat Posts: 34,361 Forumite
    Part of the Furniture 10,000 Posts Name Dropper Photogenic
    edited 4 January 2020 at 2:23PM
    Or ASME Special No 30, 11.43mm dia and 16 TPI


    My money is on a worn 12mm 1.5mm pitch ;)
  • Undervalued
    Undervalued Posts: 9,506 Forumite
    Part of the Furniture 1,000 Posts Name Dropper
    molerat wrote: »
    Or ASME Special No 30, 11.43mm dia and 16 TPI


    My money is on a worn 12mm 1.5mm pitch ;)

    Mine too!!
  • custardy
    custardy Posts: 38,365 Forumite
    Part of the Furniture 10,000 Posts Name Dropper Photogenic
    Wig wrote: »
    I don't have a thread gauge, I have used my eye
    I do have a micrometer

    threads are 11.65mm diameter (0.458")
    pitch I got 35/21 = 1.6666mm 30/18 = 1.6666mm (15+ tpi)

    What is this bolt size please ?

    You can print/check on screen a thread pitch guide

    https://www.boltdepot.com/fastener-information/Printable-Tools/US-and-Metric-Thread-Sizes.pdf
  • Wig
    Wig Posts: 14,139 Forumite
    Sorry to be late back here.

    I bought a new bit different manufacturer and the screw in there had the same thread. So I was sure it was not non standard 1.666 pitch.

    I measured the new one 11.35 mm diameter !
    and the threads were the same so I counted them again and realised my earlier mistake. I was counting the thread on 0mm as "1" so I counted 1 too many.

    35/20 = 1.75
    30/17 = 1.76

    It seems to be a very thin diameter M12 with coarse thread.
  • ohreally
    ohreally Posts: 7,525 Forumite
    1,000 Posts Combo Breaker
    What, if any, markings are on the head?
    Don’t be a can’t, be a can.
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