Pipe / Fitting Sizing
To assist in pipe sizes, the following list provides the physical measurements to identify the correct pipe size.
These measurements are of the EXTERNAL diameter of the pipe or hose (and spigot fittings, or internal diameter of socket fittings)
1/2" / 15mm - 21.4mm
3/4" / 20mm - 26.8mm
1" / 25mm - 33.5mm
1.5" / 40mm - 48.4mm
2" / 50mm - 60.5mm
These measurements are of the INTERNAL diameter of TUBING only:
3/8" / 9mm - 9mm
3/4" / 19mm - 19mm
External diameter of the barb fittings used with tubing is generally slightly larger than the bore of the tubing to ensure a tight fit.