External British Pipe Threads (Whitworth Form) Table per. BS EN ISO 228
G/R/RP-Withworth thread (BSPP/BSPT) | Teesing
Thread Identification Guide | HoseandFittings.com
Parallel Pipe Thread Limit Plug Gauge (G) | SOKUHANSHA | MISUMI South East Asia
BSP Threads
G 3/8 - 19 BSP Parallel British Standard Pipe HSS Tap by Merlintools : Amazon.co.uk: DIY & Tools
G or R or BSP | Determination – Thread Types | Screw Joints | Technical information | BOLA - Tubing, Stirrer Shafts, Magnetic Stirring Bars - Labware made of PTFE
G 3/8" - 19 Left hand Thread BSP Parallel British Standard Pipe Die D/2