BSP Thread And Its Difference From G Thread

BSP Thread is the abbreviation of the English Standard Pipe thread, referring to the British Standard Pipe Thread, which belongs to the category of Wyeth thread (BS84), and the tooth Angle is 55°. According to the shape of the BSP thread, there are two kinds of cylindrical Pipe thread BSPP (British Standard Pipe Parallel) and Taper pipe thread BSPT (British Standard Pipe Taper).

BSPP- Inch cylindrical pipe thread. Corresponding to another kind of pipe thread called "conical pipe thread", this is a conventional name, but also the standard name in textbooks.

For historical reasons, BSPP is also known by different names. Common examples include BSPF (British Standard Pipe Fitting), BSPM (British Standard Pipe Mechanical), and PS (British Standard Pipe Straight). Later, with the beginning of ISO standardization, these names were all replaced by a simple and clear letter G, which is the G thread. Therefore, BSPP, BSPF, BSPM, and PS are now collectively referred to as G threads.

The reason why it is called G thread is because the thread was originally used on the Gas pipe, and the English word for gas is Gas, but some people say that G comes from the abbreviation of German Gewinde (meaning thread), in addition, the first letter of G and Chinese pipe (Guan) pinyin is the same, so the origin of G thread seems to make sense from any point of view. It really is a coincidence.

G thread is divided into internal and external threads for non-sealed connection. The implementation standard is BSENISO228-1, and the old standard is BS2779, which is now obsolete.

BSPT- Inch taper pipe thread, also known as PT thread, is only used for general sealing connections. The old BSPT standard is BS21, and in the new standard BSEN10226-1, R thread is used instead. So R thread is BSPT and PT thread collectively.

The letter R in the R thread is derived from the German rohr (German for "tube"). R thread is actually a series, common Rp, Rs, Rc, R1 and R2. The details are as follows:
Rp- Inch seal cylindrical internal thread
Rs-inch seal cylindrical external thread
Rc-inch seal taper internal thread
R1-inch sealed taper external thread for use with Rp, i.e. Rp/R1 "column/cone" fit
R2-inch sealed taper external thread for use with Rc, i.e. Rc/R2 "taper/taper" fit
It can be seen that the general seal pipe thread is divided into two kinds of cylindrical pipe thread and conical pipe thread.

Cylindrical pipe thread (Rp) for sealing is designed to be exactly the same shape as unsealed pipe thread G, the difference is the precision of the thread. The taper pipe thread (R) for sealing is transformed on the basis of cylindrical pipe thread according to 1:16 taper.