Under normal circumstances, the hexagon socket bolts can be divided into normal and high strength according to the grade, while the ordinary hexagon socket bolts refer to 4.8 grades, and the high-definition hexagon socket bolts refer to grades 8.8 or above.
Hexagon bolt performance grades can be divided into: 3.6, 4.6, 4.8, 5.6, 6.8, 8.8, 9.8, 10.9, 12.9 and other more than 10 grades, of which 8.8 and above bolts are made of low carbon alloy steel or medium carbon steel. Heat treatment (quenching, tempering), commonly known as high-strength bolts, the rest are commonly referred to as ordinary bolts. The bolt performance grade label is composed of two parts, which represent the nominal tensile strength value and the yield ratio of the bolt material. For example, a bolt with a performance level of 4.6 means:
1. The nominal tensile strength of bolt material is up to 400MPa;
2, the bolt material has a yield ratio of 0.6; the bolt material has a nominal yield strength of 400×0.6=240 MPa.
Performance grade 10.9 high strength bolts, after heat treatment, can achieve:
1. The yield ratio of the bolt material is 0.9; the nominal yield strength of the bolt material is 1000×0.9=900 MPa;
2. The nominal tensile strength of bolt material is up to 1000MPa. Elephant.