Expansion bolt

Expansion bolts are a special type of threaded connection used to fix pipe supports, hangers, brackets or equipment to walls, floors or columns. The grades of carbon steel bolts include more than ten levels such as 3.6, 4.6, 4.8, 5.6, 6.8, 8.8, 9.8, 10.9 and 12.9. The numbers before and after the decimal point respectively represent the nominal tensile strength and the yield ratio of the bolt material. For example, a bolt marked as grade 8.8 indicates that the material's tensile strength reaches 800 MPa and the yield ratio is 0.8, meaning its yield strength is 800 x 0.8 = 640 MPa.