How to understand the various specifications of bolts?

Bolts are often used in hardware fasteners, but there are many kinds of bolt sizes, different areas of the use of bolts are different, if the bolt is too large or too small will not be used. So what are the specifications and models of bolts? How is it represented? Let's look at that in a moment.

1. Specification and representation of bolts

Bolt specifications are generally indicated by the letter "M", including M6, M8, M10, M12, M14, M16, M18, and M20. Taking M 16-5g6g as an example, it means that the nominal diameter of the ordinary thread is 16cm, right-handed, the tolerance zone is 5g, and the large diameter is 6g. If it is M16×1 LH-6G, it represents the fine thread, the nominal diameter is 16, the pitch is 1cm, the left turn, the large diameter is 6G, and the spinning length is considered according to the medium length.

Second, what are the types of bolts

1, according to the force points, there are ordinary bolts and bolts for reaming holes.

2, according to the shape of the head, can be divided into hexagonal, square, round, and countersunk... Among them, hexagonal bolts are more common.

3, according to the thread type is divided into coarse teeth, fine teeth two kinds.

4, according to the bolt performance level can be divided into 3.6, 4.8, 5.6, 8.8, 10.9 and 12.9, etc., 8.8 grade above the low carbon alloy steel bolts, with high strength, and 8.8 grade below the ordinary bolt.

5, according to the precision of bolt production is divided into three levels, respectively, A, B, C, belongs to refined bolts, often used in lathe processing, the general performance grade is 8.8, C belongs to rough bolts, grade is 4.8, often used in temporary fixing.

About the specifications and models of bolts and their presentation methods and types, we will introduce them here, and hope to help you. Although the size of the bolt is relatively small, it hides a lot of energy. If you pick the wrong screw, it won't work