HoseFitFinder

1-1/2" BSP parallel (G1-1/2 / BSPP) (G1-1/2)

Where G1-1/2 is used, its real dimensions, and how to connect it to other standards.

G1-1/2Thread standard
DesignationG1-1/2
Major diameter47.803 mm
Threads per inch / pitch11
Thread formparallel, 55 degree
Seals onflat washer or bonded seal on the face

Used on: large transfer pumps, tank flanges and IBC plumbing.

G1-1/2 at 11 TPI is a large-bore transfer thread. On IBC and tank work it is usually reached through an S60x6 buttress-to-BSP adapter rather than cut directly.

Quick-connect click fittings from Hozelock, Gardena and Karcher are proprietary and do not interchange. They all sit on top of a standard thread underneath, so the reliable way to move between brands is to adapt at the threaded tap or hose-end fitting, then use each brand's own connector above it.

Connect this thread

Sources: ISO 228-1 (G / BSPP parallel pipe threads) · BSP thread dimensions chart (ISO 228 / ISO 7), AmesWeb