Pipe thread chart: inch / mm conversion (BSP, 15/21, 20/27, S60x6)

A “1/2 inch” thread measures 20.96 mm, not 12.7: in plumbing, the inch size is not converted, it is read from a chart. Here you will find the inch / mm correspondence of every common thread (BSP or “gas thread”, French names 15/21 · 20/27 · 26/34, NPT, S60x6 IBC tanks, Guillemin, Camlock, PVC), a tool that identifies your thread and the fitting that goes with it, and the pitfalls to avoid.

No need to know the name of your thread. Just answer the question: what do you need to connect to?

A 1000 L IBC tank The big square tank in its metal cage. The most common case. S60x6 — 8 times out of 10 A wide-mouth tank Same type of tank, but the drain cap is as wide as a hand. S100x8 A garden hose The classic garden tap, or a tap connector. 1/2" · 3/4" · 1" Plumbing A threaded steel or brass pipe, 1/2", 3/4", 1"… All sizes, from 1/4" to 4" A quick connector The garden hose connector that clicks on with a quarter turn, no tools. Gardena type A lever coupling Two metal arms that fold down. Tanks, tankers, industry. Camlock A fire hose coupling Symmetrical coupling with a locking lug, in aluminium. Irrigation, fire fighting. Guillemin DN I'd rather measure You have the part in hand and a caliper or a tape measure? Measurement in mm