Shorten steel gas pipe without rethreading?

[JohnD]

It is, because I measured it with a digital caliper. In fact it's 21.87mm.

imperial steel pipe is specified by the nominal internal bore, in inches and fractions thereof. what's yours?

nominal because the as-built wall thickness was reduced after the first standards were laid down.

guess what the OD of half-inch steel pipe is.

22mm copper pipe is specified by the nominal external diameter in mm.

 

[FiremanT]

It is, because I measured it with a digital caliper. In fact it's 21.87mm.

Precisely. I told you it was not 22mm. I could have told you that without seeing a picture or even reading the comments.

 

[FiremanT]

It is, because I measured it with a digital caliper. In fact it's 21.87mm.

Now, I have never actually measured steel pipe, so am only going on the charts. But I would test your callipers against a known measurement. The OD should be 21.336 (O.84"). It is 1/2" pipe, which is measured internally, as think JD says.

I've locked this thread and can only advise the OP that he needs to cut the cupboard or get an RGI involved who has the ability to rethread the pipe. Make sure you let them know in advance as I would suspect that less than half domestic installers can do this nowadays.

Kind regards

Mod