At 10:56 +0000 on 01/08/2014, Mike Kerford-Byrnes wrote about SI units and such:
A few years ago I attempted to purchase 225 yards of water pipe from a plumbing merchant, only to be told (in no uncertain terms) that only metric lengths were available. Somewhat chastened, I mentally converted and asked for 200 metres of water pipe. The response? "Half inch or three-quarters?"
I see no problem with the question. The pipe is still made in half and three-quarter diameters (not metric diameters) since it is a standard item and needs to work with older fittings/etc. The lengths however have switched over to metric lengths.
............ MKB
