Results 1 to 5 of 5

Thread: "R1/4" thread. What is it?

  1. #1
    Forum Founder GarethW's Avatar
    Join Date
    Jul 2009
    Location
    Cambridge, UK
    Posts
    1,340
    Blog Entries
    7

    Unhappy "R1/4" thread. What is it?

    I need to fit this part (pictured below) to something. It has a "R1/4" thread. Anyone know what that means? Is it an ordinary 1/4" BSP thread or is it some kind of fancy thread with non-parallel sides?

    .



  2. #2

    Re: "R1/4" thread. What is it?

    Gareth

    The 'G' and 'R' thread designations were added when BSP threads were adopted by the metric system for pipe threads.

    'G' is the same as BSPP (parallel thread), 'R' is the same as BSPT (tapered thread).

  3. #3
    Forum Founder GarethW's Avatar
    Join Date
    Jul 2009
    Location
    Cambridge, UK
    Posts
    1,340
    Blog Entries
    7

    Re: "R1/4" thread. What is it?

    Thanks for the help. I had some samples come through today in the post. The overall diameter of the thread measures more like 1/2", so I'm pretty confused about the "1/4" designation. I made some measurements in metric: the diameter of the thread is 12.9mm at the top, tapering up to 13.3mm at the base. The length of the threaded part is 11mm. I'll drop the samples off to a machinist on Tuesday. Hopefully he can cut the right type of female thread for me.

  4. #4

    Re: "R1/4" thread. What is it?

    Gareth

    BSP Pipe threads are sized according to the thread that can be machined onto that size bore pipe, so a 1/4" BSP thread measures 0.518" or 13.15mm

    Tapered threads are used when a shoulder is not available to seal against like threading the OD of a pipe and should be screwed into a female tapered thread.

    Tapered threads are prone to leakage but have the benefit of being positional.

  5. #5
    Look at this...

    or this

Similar Threads

  1. Unit converter - "Convert" by Josh Madison
    By GarethW in forum Calculations
    Replies: 2
    Last Post: 1st Feb '12, 03:01
  2. Senior "Creative" Mechanical Design Engineer
    By Joshua @ Glotel in forum Europe jobs
    Replies: 0
    Last Post: 14th Sep '11, 11:01
  3. Which is better: a "lightweight" design or a "green" design?
    By GarethW in forum The main mechanical design forum
    Replies: 10
    Last Post: 7th Sep '11, 13:40
  4. "Britain needs to copy the French and love its engineers"
    By GarethW in forum Mechanical Design news & events
    Replies: 5
    Last Post: 18th Dec '10, 15:47
  5. "Similar Topics" - a nice new forum feature
    By GarethW in forum Help, info & forum announcements
    Replies: 0
    Last Post: 17th Oct '10, 18:21

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •