What are the different types of hexagonal bolt threads?

Hex bolt thread have those thread as below :

1. International Metric Thread System:
China's national standard CNS uses the thread. The crest is flat, easy to turn, and the bottom is
It is rounded to increase the thread strength. The thread angle is 60 degrees and the specification is indicated by M. public
Threads can be divided into coarse and fine teeth. The representation is as M8x1.25. (M: code, 8: public
Weigh the diameter, 1.25: pitch).
2. American Standard Thread:
Both the top and the root of the thread are flat and have good strength. The thread angle is also 60 degrees, and the specifications are
There are a few teeth per inch. Such threads can be divided into coarse teeth (NC); fine teeth (NF);
(NEF) Level 3. The representation is 1/2-10NC. (1/2: outer diameter; 10: number of teeth per inch; NC
Code name).
3. Unified Thread:
It is jointly developed by the United States, the United Kingdom, and Canada, and is the commonly used inch thread.
The thread angle is also 60 degrees and the specification is expressed in a few teeth per inch. Such threads can be divided into coarse teeth
(UNC); fine teeth (UNF); ultrafine teeth (UNEF). The representation is 1/2-10UNC. (1/2:
Outer diameter; 10: number of teeth per inch; UNC code)
4.V-shaped thread (Sharp V Thread):
The top and the root are pointed, the strength is weak, and it is not often used. The thread angle is 60 degrees.
5. Whitworth Thread:
Threads used in British national standards. The thread angle is 55 degrees, indicating the symbol is "W".
Suitable for rolling method manufacturing. The representation is as W1/2-10. (1/2: outer diameter; 10: number of teeth per inch;
W code).