Threads - BSP - Parallel - Tapered - BS746

[Rich]

Could someone please post a definition of all these different types of
thread.
I have searched Google and have come up with some basic, but
confilicting, information.

It would also be a great addition to the FAQ.

All i have come up with;

BSP - British Standard Pipe. Parallel thread.
BSPT - BSP Tapered Thread.

What is the difference between a parallel and tapered thread? How,
looking at a male or female thread, would you determine this?
What part of a fitting, and how, would you need to measure to
determine the thread size.
What size and type of thread do you get on a 15mm compression coupler?
1/2" BSP Parallel Thread? The actual thread does not measure 1/2" but
the internal diameter of the 'pipe' does!

Do parallel male and female threads go together? Or is it parallel to
female only?

When should and should not a fibre washer be used?

PTFE or Sealing Compound?

What is a BS746 thread?

Rich

[Phil Addison]

On 8 Jul 2003 08:26:29 -0700, in uk.d-i-y rich_ar...@yahoo.co.uk

(Rich) wrote:
>Could someone please post a definition of all these different types of
>thread.
>I have searched Google and have come up with some basic, but
>confilicting, information.

Here's a few starting points...

Ian Wright's "A Compilation of Thread Size Information"
http://www.watchman.dsl.pipex.com/thread.html

Maryland Metrics Screw threads, overview
http://mdmetric.com/fastindx/t44u.pdf

Maryland Metrics Thread Identification Chart
http://mdmetric.com/tech/tic1e.htm

Brian Morgan's Screw Thread Data
http://members.lycos.co.uk/A10bsa/intro.htm

John Paquay's Wood Screw Sizes and Pilot Holes
http://home.insightbb.com/~jpaquay/scruchrt.html

>It would also be a great addition to the FAQ.

If you give me the info you gather, I'll see what I can do.

>All i have come up with;
>
>BSP - British Standard Pipe. Parallel thread.
>BSPT - BSP Tapered Thread.
>
>What is the difference between a parallel and tapered thread? How,
>looking at a male or female thread, would you determine this?
>What part of a fitting, and how, would you need to measure to
>determine the thread size.
>What size and type of thread do you get on a 15mm compression coupler?
>1/2" BSP Parallel Thread? The actual thread does not measure 1/2" but
>the internal diameter of the 'pipe' does!
>
>Do parallel male and female threads go together? Or is it parallel to
>female only?
>
>When should and should not a fibre washer be used?
>
>PTFE or Sealing Compound?
>
>What is a BS746 thread?

--
Phil Addison
The uk.d-i-y FAQ is at http://www.diyfaq.org.uk/
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