# What is an R thread?

## What is an R thread?

These are parallel threads (BSPP), which have a constant diameter, which are known a G threads, and taper threads (BSPT), whose diameter increases or decreases along the length of the thread, known as R threads.

Is ISO thread the same as BSP?

ISO metric machine threads should be used instead of pipe threads for mechanical fastenings such as bolts and nuts. BSP (British Standard Pipe) threads, using the Whitworth thread form, have been adopted as the ISO standard for pipe threads, and will hereafter be called out as ISO and not as ESP.

British Standard Pipe (BSP) is a set of technical standards for screw threads that has been adopted internationally for interconnecting and sealing pipes and fittings by mating an external (male) thread with an internal (female) thread.

### Are BSP and gas threads the same?

BSPP or Gas thread. Parallel threads: also called straight threads. These threads have a constant diameter, commonly known as parallel threads. These threads are called BSPP or Gas (remember that the P at the end stands for Parallel as a rule to differentiate it from the tapered thread).

Is R thread same as NPT?

NPT threads are common in the United States and a few other countries, BSP threads (also know as the R subset according to ISO 7) are widely used in many other countries.

British Pipe Thread ( Whitworth Form) — Taper (BSPT)
Thread Designation BSPT Nominal Size BSPT Minor Diameter Male Thd. d3
R 1 1″ 30.291
R 1 1/4 1 1/4″ 38.952
R 1 1/2 1 1/2″ 44.845

#### Is ISO thread the same as NPT?

NPT Threads. ISO threads are identical to British Standard Pipe Threads. Although they may appear identical to NPT threads in size and dimension, they feature a slightly different pitch (distance between threads).

British Pipe Thread ( Whitworth Form) — Taper (BSPT)
R 1 1/2 1 1/2″ 11
R 2 2″ 11
R 2 1/2 2 1/2″ 11

## Can you use BSP with NPT?

NPT/NPS and BSP threads are not compatible due to the differences in their thread forms, and not just the fact that most sizes have a different pitch.

Can you screw BSP into NPT?

How do you convert BSP to NPT?

BSP thread 1/2 Inch to NPT thread 1/2 Inch – threaded pipe fitting adaptor which will let you convert the BSP(UK) or G (European) thread to NPT American standard thread or other way round. You would need to just screw this adaptor into existing male thread and you will end up with other standard thread.

### Can you screw NPT into BSP?

Can BSPT fit into NPT?

BSPT Connections Another important difference is that for many BSPT pipe sizes the thread pitch is different than NPT. Thus an NPT male will sometimes fit into a BSPT fitting or vice versa but they will not seal.

• August 14, 2022