Thread Data

There are 4 main types of thread used today in the pneumatic and vacuum cup industry. The following (NPS, NPT, BSPP and BSPT) will highlight the technical data that should be understood when applying these thread types for use with pneumatics and vacuum cup fitting.

National Pipe Taper (NPT)

Referred to as NPT. This is the most common thread used in America, and is the standard for USA and Canada. This tapered thread is sealed with sealant or tape.

Thread Taper Angle 1° 47'
Thread Angle 60°
Thread Crest & Root Flat

National Pipe Straight (NPS)

Referred to as NPSF (National Pipe Straight Fuel). NPSF is often used in fuel line connections or in the pneumatics industry.

Thread Taper Angle
Thread Angle 60°
Thread Crest & Root Flat

British Standard Pipe Parallel (BSPP)

Often denoted by the letter G, this thread form is the most popular female thread for pneumatic components throughout the world. With the parallel thread, the male fittings is sealed with an O ring to ensure a perfect seal every time, as well as with manifolds to ensure a common fitting height. This also allows for reusability without the need for applying thread sealant, or teflon tape. Male G threads cannot be connected to female R thread ports.

Thread Taper Angle 1° 47'
Thread Angle 55°
Thread Crest & Root Radius

British Standard Pipe Taper (BSPT)

Often denoted by the letter R, this thread form is the most popular pipe thread for pneumatic components throughout the world. With the tapered thread, the male fitting can be connected to both BSPT, and BSPP thread female forms. The prefered interface is betweeen BSPT male to BSPT female for a full tapered seal. BSPT threads need a thread sealant to seal.

Thread Taper Angle
Thread Angle 55°
Thread Crest & Root Radius

Female Threads
Parallel Taper American
BSP/BSPP RP PF G BSPT Rc PT NPT NPTF
Male Threads BSP/BSPP Y Y Y Y N N N N N
BSPT Y Y Y Y Y Y Y N N
G Y Y Y Y N N N N N
NPT N N N N N N N Y N
NPTF N N N N N N N N Y
PF Y Y Y Y N N N N N
PT Y Y Y Y Y Y Y N N
R Y Y Y Y Y Y Y N N
UNI Y Y Y Y Y Y Y Y Y