1.1 This specification covers two types of quenched and tempered, steel, metric heavy hex structural bolts having a minimum tensile strength of 830 MPa (Note 1). 1.2 The bolts are intended for use in structural connectio This specification covers two types of quenched and tempered, steel, metric heavy hex structural bolts. The bolts are intended for use in structural connections. The bolts are furnished in sizes M12 to M36 inclusive. They are designated by type denotin