1.1 This specification covers two types of quenched and tempered alloy steel, metric heavy hex structural bolts having a tensile strength of 1040 to 1210 MPa. 1.2 These bolts are intended for use in structural connectio This specification covers the chemical, mechanical, and metallurgical requirements for two types of heavy hex structural bolts made of quenched and tempered alloy steel and having specified tensile strengths and sizes. These bolts are intended for use