annoying metric conversions

[Jim Lawton]

I was recently plumbing a new sink in the kitchen. I almost fell foul of the wonders of imperial nomenclature applied to metric fittings when I selected a

1/1/2" drain (the bit that fits the hole in the sink) and a 1/1/2" bottle trap ....

both from Mr B&Q

When I suddenly noticed, that the drain was threaded 38mm, and the bottle trap was 40mm

How stupid is that :-)

-- Jim "a single species has come to dominate ... reproducing at bacterial levels, almost as an infectious plague envelops its host"

[shazzbat]

It sounds to me like you've got one at 1 /1/4" and t'other at 1/ 1/2". I agree though about the confusion with sizes. Imperial sizes referred to the bore of the pipe, whereas metric ones refer to the O.D. It confused the hell out of me when it first started changing, because I'm not a plumber, I'm a mechanic, and therefore I know that an inch is 25.4mm, not 28.

Steve

[Jim Lawton]

If only - they both said in big friendly letters on the top 11/2" !!!

I

-- Jim "a single species has come to dominate ... reproducing at bacterial levels, almost as an infectious plague envelops its host"

[D. A. Hicks]

worrying that the UK turned metric some 30 years ago eh ?

[BigWallop]

And it was being taught in schools for many years before that to get the next generation ready for the change. It was amazing to see kids in the shops tell their mothers and fathers what the conversions of the new money and weights were. :-)

[shazzbat]

It doesn't worry me. I went to school in imperial, but trained as a mechanic in SI. The only thing that bothers me is the plumbing sizes which are wrong. As I said earlier, an inch is not 28 mm, it's 25.4. There is a very good reason for pipe sizes being quoted by the bore size, because a pipe of X bore will pass the same amount of fluid regardless of the OD, which can then change to allow for different pressure requirements.

I'm quite happy to work in either system, or both according to convenience. If I want to cut a piece of metal and I measure the required size with a tape rule, I can cut it to 200(mm) x 18 (") and it fits. Result.

Steve

[D. A. Hicks]

I was not "having a go" shazzbat, simply stating that we have had metric measures in out midst for some 30 years, and still getting problems ??????

Like you I work in both Metric in UK and Europe and the antiquated Imperial when stateside, now that does cause some confusion !

[shazzbat]

I know. I wasn't offended.

And have you, like me, still got Whitworth spanners available?

Steve

[BigWallop]

Yes, and a set of sockets and box spanners. I still use them quite often in fact. :-)

[Blueyonder]

What's 'metric' ? - never heard of it !!!

[D. A. Hicks]

Met-Tric is what the London police do to catch criminals ! ( whoops, did I say that out loud )

[BigWallop]

LOL!!! Your coat's over there >>>>>>>>>>>>>>> LOL!!!

[Jim Lawton]

In that case it's prolly what you passed instead of "O" Level :-)

-- Jim "a single species has come to dominate ... reproducing at bacterial levels, almost as an infectious plague envelops its host"