Specifications, Models And Representation Methods, And Types Of Bolts

First, the specifications and representation of bolts

The specifications and models of bolts are generally represented by the letter "M", and the specifications are M6, M8, M10, M12, M14, M16, M18, M20, etc. Take M 16-5g6g as an example, it means that the nominal diameter of the common thread is 16cm, right-handed, the middle diameter of the tolerance zone is 5g, and the major diameter is 6g. If it is M16×1 LH-6G, it represents fine thread, the nominal diameter is 16, the pitch is 1cm, left-handed, the major diameter is 6G, and the screwing length is considered according to the medium length.

Second, what are the types of bolts?

1. According to the stress, there are ordinary bolts and bolts for reaming holes.

2. According to the shape of the head, it can be divided into hexagonal, square, round, and countersunk heads... Among them, the hexagonal is the more common bolt.

3. According to the thread type, it is divided into two types: coarse teeth and fine teeth.

4. According to the bolt performance grade, it can be divided into 3.6, 4.8, 5.6, 8.8, 10.9, 12.9, etc. The bolts above grade 8.8 belong to low carbon alloy steel bolts with high strength, while those below grade 8.8 are ordinary bolts.

5. According to the bolt manufacturing accuracy, it is divided into three grades, namely A, B, and C, which belong to refined bolts and are often used in lathe processing. fixed.