Designed for use in structural joints, these bolts are made from hardened steel and meet ASTM A-325 specifications. Hot dipped galvanized finish available. Stocked in diameters from 1/2" to 1-1/4” and lengths to 6". Head markings for an A-325 bolt is a stamped “A325” somewhere on the head. See common head markings (link) for hex bolt grade differences.