As we all know, the strength of bolts can be divided into several levels. The more common ones are 4.8, 8.8, 10.9, and 12.9. It is necessary to determine whether its strength meets the requirements for use. If the strength does not meet the standard, it will lead to premature breakage and damage to the bolt. So how does Heavy Hex Bolt judge strength?
Generally, the hexagon socket head cap bolts of grade 4.8 are called ordinary type, and those exceeding grade 8.8 can be called strength socket head cap bolts. Many steel structure construction occasions require the use of high-strength bolts to meet practical applications. How to judge the strength of hexagon socket head bolts and "preload" these two parameters. But many people can easily fall into the misunderstanding. Many people think that if the material grade exceeds 8.8, then the bolt must also be of high strength. In fact, the main criterion for high-strength socket head bolts is not the strength of the material itself, but its stress form. As for the stress form, in simple terms, it is The pre-tightening force that the bolt can apply and the static friction the shear resistance is obtained by the hand in the rubbing state, so the strength cannot be judged simply by the material.
There are also many people in the industry who think that strength is determined by high rigidity, safety, and damage resistance. In fact, it is not the case. The strength of the bolt is actually determined by its bearing capacity. High-strength socket head bolts should have high joint stiffness and elasticity. The deformation is small, so under combined load conditions, even if the number of bolts does not change, it is still suitable for high-strength rings used in the environment.