There is a difference between the seals of the two main thread types, the NPT and theBSP.

The difference between the two threads has more to do with where you live.The standard for screw threads used on pipes and pipe fittings is called the NPT.

The peaks and valleys are familiar to both threads.There are two fundamental ways in which the designs of the threads differ.The peaks and valleys of the threads are flat.They are rounded.The NPT angle of the thread is 60 degrees and the BSP angle is 55 degrees.

The U.S. has a standard for tapered threads used to join pipes and fittings.The American National Standard Pipe Thread established them as a standard.One of the U.S. national technical standards for both straight and tapered thread is called NPT.

The British Standard Pipe is referred to as BSP.A number of technical standards for screw threads that have been adopted internationally are defined by the ISO 228 standard.It has become a standard in plumbing and pipe fitting.

The need to standardize earnest screw threads began with the Industrial Revolution.It was necessary to have a standard for compatibility between manufacturers and users.

William Sellers established the U.S. standard for tapered threads.He proposed a set of new standards for nuts, bolts and screws to replace the poorly standardized screw thread practice in the U.S.

In 1841, Joseph Whitworth proposed a thread design that was quickly adopted by many British railroad companies and became a national standard for the United Kingdom called British Standard Whitworth.