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My local hardware store stocks 15mm diameter galvanised pipe fittings and lengths of galvanised pipe with threaded ends. The annoying thing is they charge $7 for a 100mm length of pipe but $16 for a 900mm length. I bought a 900mm length thinking I'd get a die set and cut and thread my own lengths.

The hardware store didn't stock and dies big enough for 15mm pipe. I've spent the last two evenings searching around for a pipe threading set with a die for 15mm pipe but can't seem to find such an item. Most of the dies I've come across are in inches rather than mm which I suspect won't work with the fittings I've got.

Can anyone give me any pointers as to whether a pipe threading tool for 15mm diameter pipe really is that exotic or where such beasties are likely to be found?

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Is 15mm the inner or outer diameter? Dies are sold by OD, but pipe is often measured in ID. McMaster-Carr lists metric dies, but only in even mm sizes from 10 to 24mm. They also have dies for pipe, but not in metric. – Joe Jul 31 '13 at 14:47
15mm is the metric equivalent of 1/2 inch nominal pipe size. I've no way to be sure, but I believe you need a 1/2" BSPT (British Standard Pipe - Tapered) die. – bcworkz Jul 31 '13 at 19:48
15mm is the inner diameter. The outer diameter is 20mm. 3/4 inch is close to 20mm so maybe I should bite the bullet and look for a 3/4" die. – sipwiz Aug 1 '13 at 10:19

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