PUSH-ON

British Standard Pipe Parallel (BSPP) threads, also known as Whitworth threads, are among the most widely used thread types. The BSPP (parallel) male mates with a BSPP (parallel) female or a female port. The BSPP male has straight threads and a 30° seat. The BSPP female has straight threads and a 30° seat. The BSPP female swivel fitting has a tapered nose that seals against the male cone seat. The BSPP (parallel) connector is similar to, but not interchangeable with, the NPSM connector. In most sizes, the thread pitch is different, and the thread angle is 55° instead of the 60° angle used on NPSM threads.

This is a dryseal thread, the National Pipe Taper Fuel (NPTF) thread, used on both male and female fittings. Although it is still widely used in fluid power systems, it is not recommended by the National Fluid Power Association (NFPA) for hydraulic applications. The NPTF male mates with NPTF, NPSF, or NPSM females. The NPTF male has tapered threads and a 30° inverted seat. The NPTF female has tapered threads and no seat. Sealing occurs through thread deformation. The NPSM female has straight threads and a 30° inverted seat. Sealing occurs on the 30° seat. The NPTF connector is similar to, but not interchangeable with, the BSPT connector. In most sizes, the thread pitch is different. The thread angle is 60°, compared with the 55° angle of BSPT threads.

A metric standpipe assembly consists of three components assembled onto a male fitting: a standpipe, a bite sleeve, and a metric nut. The metric nut is fitted onto the standpipe, followed by the bite sleeve. For DIN light series assemblies, a DIN light metric nut is generally used, while DIN heavy series assemblies require a DIN heavy metric nut. The bite sleeve and standpipe are selected according to the tube outer diameter (OD).