U.S. Bolt type chain shackes 1.Material: carbon steel after dropping forged, quenched and tempered. 1. Bolt Type Chain Shackles with thin head bolt-nut with cotter pin. Meets the requirements of Federal Specification RR-C-271D type IVA, Grade A, Class2.2. Material:Drop forged carbon steel, quenched and tempered.3. Max proof load is 2.2 times the Working Load Limit, Min Break Strength is 6 times ...