Lobster wrote:
I've noticed two different types of these; some are apparently made of
brass and have a completely rounded external profile, whereas others
seem to be copper, and have flat chamfers at either end.

Can anyone tell me the significance of the two species, and are they
interchangeable in different compression fittings?

Thanks
David

Brass for gas couplings i.e fires ect and copper for water pipes i.e taps
ect.

--
Sir Benjamin Middlethwaite