1/2" NPT (National Pipe Taper) (1/2-14 NPT)
Where 1/2-14 NPT is used, its real dimensions, and how to connect it to other standards.
1/2-14 NPTThread standard
Designation1/2-14 NPT
Major diameter21.34 mm
Threads per inch / pitch14
Thread formtapered, 60 degree
Seals onon the thread flanks with PTFE tape
Used on: US plumbing, irrigation valves and pump ports.
1/2 NPT at 14 TPI is a mainstay US plumbing thread. It shares the 14 TPI count of G1/2 but the 60 degree taper means the two do not mate without an adapter.
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
Connect 1/2" NPT (National Pipe Taper) to 1/2" BSP parallel (G1/2 / BSPP)needs an adapterConnect 1-1/2" NH fire hose thread (NST) to 1/2" NPT (National Pipe Taper)needs an adapter1/8" NPT (National Pipe Taper)related standard (1/8-27 NPT)1/4" NPT (National Pipe Taper)related standard (1/4-18 NPT)3/8" NPT (National Pipe Taper)related standard (3/8-18 NPT)3/4" NPT (National Pipe Taper)related standard (3/4-14 NPT)1" NPT (National Pipe Taper)related standard (1-11.5 NPT)1/2" BSP parallel (G1/2 / BSPP)often confused with 1/2-14 NPT
Sources: ANSI/ASME B1.20.1 (NPT pipe threads) · NPT thread dimensions chart (ASME B1.20.1), Machining Doctor