What is the meaning of 6H in thread M 10-6H?

6H is the thread tolerance level. There is generally no thread, followed by the capital letter "H".

GB/T 197-2003 stipulates the basic deviation of internal and external threads to determine the position of the tolerance zone of internal and external threads relative to the basic tooth profile.

The four basic deviations of external thread are indicated by codes H, G, F and E, and the two basic deviations of external thread are indicated by H and G. (Refer to GB/T 197-2003).

The extended data m is the thread code. Generally speaking, threads can be divided into coarse threads and fine threads according to pitch. M 10: coarse thread with nominal diameter of 10. The pitch of coarse thread is not marked, and the pitch of M 10 is1.5 mm.

Fine thread must be marked, such as: M 10× 1: nominal diameter is 10 and pitch is 1 (fine thread). M 10× 1-LH means: nominal diameter10, pitch1,left-handed thread (left-handed thread is denoted by LH).

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