Oh - the 1 1/2" on the outside of the box is for the saddle type (middle picture above) - I don't know the internal diameter of that. The F42 with the internal dia. of 2" are in the first picture above. I did see the unlined steel clapms when I was searching but they have a different base shape completely.
Is the latter still true of metric steel pipe (if it exists - I've never had reason to look!)?
I ask because, with copper pipe, the change from Imperial to metric obviously resulted in a change from sizing it by ID to sizing it by OD - which is why, for example, 15 mm and ½" copper pipe have almost the same OD (such that the same olives will fit both), even though ½" is 12.7 mm.
Yes, sized by the nominal inner bore.
Copper is sized on the outer diameter, but is tube rather than pipe, despite being often called pipe.
Steel is pipe, copper is tube.
Pipe is inner bore, tube outer diameter.
Mind you, as I said, even if it is tube rather than pipe, 'the copper one' changed from inner bore to outer diameter size specification when we moved from Imperial to metric, didn't it? ... or are you saying that it also changed from pipe to tube at that time?
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