Grade performance of external hexagon bolt

The performance grade label of the external hexagon bolt consists of two parts, which respectively represent the nominal tensile strength value and yield ratio of the bolt material.

For example, a bolt with performance class 4.6 means:

a. The nominal tensile strength of the bolt material is 400MPa;

B. The yield ratio of bolt material is 0.6;

C, bolt material nominal yield strength of 400 × 0.6 = 240MPa grade

Performance grade 10.9 high-strength bolts, the material after heat treatment, can reach:

a. The nominal tensile strength of bolt material shall reach 1000MPa;

B. The nominal yield strength of the bolt material is 1000 × 0.9 = 900MPa.