One of the thread standards, divided into two types according to the shape of the cylinder, cone; according to the angle of the tooth type 55 °, 60 ° two. The 1/4, 1/2, and 1/8 marks in the thread are the diameters of the thread size in inches. One inch is equal to 8 points, 1/4 inch is 2 points, and so on.
Screws
Thread standard NPT, PT, G are pipe thread.
NPT is an abbreviation of National (American) Pipe Thread and is a US standard 60 degree taper thread used in North America. National standards can be consulted GB/T12716-1991
PT is the abbreviation of Pipe Thread. It is a 55 degree sealed taper thread and belongs to the family of Wyeth's thread. It is mostly used in European and Commonwealth countries. Commonly used in the water and gas pipe industry, taper is specified as 1:16. The national standard can be consulted GB/T7306-2000
G is a 55-degree non-threaded seal pipe thread, which belongs to the family of Wyeth. Marked as G for cylindrical thread. National standards can be consulted GB/T7307-2001
In addition, the 1/4, 1/2, and 1/8 marks in the thread refer to the diameter of the pipe, and the unit is inches.
The in-line person usually refers to the thread size in points, one inch is equal to 8 points, 1/4 inch is 2 points, and so on.
G seems to be the collective name of the pipe thread. The division of 55,600 degrees is a functional one, commonly known as a pipe circle. That is, the thread is machined from a cylindrical surface.
ZG is commonly known as the tube cone, that is, the thread is formed by a conical surface. The general water pipe connector is like this
Rc indicates internal thread of cone
ZG stands for taper thread, 3/4" indicates the inch mark, is 3/4 inch taper thread, "hardware manual".
Its inner diameter is exactly 19.05 millimeters, but this is the old standard and it is no longer needed. The current national standard specifies that the internal diameter of the ZG3/4 thread is 20 mm.
Its representation method should be: ZG3/4. Where (〃) is the symbol of inches.
One inch is equal to 25.4 mm. One inch equals 8 cents. The history of 3/4 is 6/8=3/4. Commonly known as 6 points.
The same ZG1/2 inch thread pipe inner diameter ≈ 15 mm. Commonly referred to as 4 points.
The inner diameter of the ZG1 thread is ≈25 mm. Commonly known as 1 inch.
The inner diameter of the ZG11/2 thread is 32 mm. Commonly known as 1 inch and a half.
Taper threads are used only for hydraulic system connections; pipe threads G3/4 are used only for pipe connections. Taper thread and pipe thread are very similar, the difference is only taper. DN is the nominal diameter