Dave Liquorice wrote:
On Thu, 23 May 2013 11:57:38 +0100, Dave Baker wrote:

I want to buy a hose pipe to attach to the outdoor tap at my new house.
Thread size measures up at about 30mm o/d and a tad less than 2mm pitch
which doesn't seem to be any normal BSP size.

In the sheds what you can buy will fit... I thought they where 3/4" BSP
but thinking about it that is the same a washing machine conector which
is smaller, so 1" BSP.

Wikipedia has 1" BSP as 11 threads/inch 1.309 inches dia (2.309 and
33.249 mm). Have you measured yours or just eyeballed it?

Knowing the OP reputation as a precision engineer, I'd assumed his
measurements to be reasonably accurate.
About 30mm o/d and less than 2mm pitch stacks up with 7/8" BSP x 14tpi.
Bob