Forged Steel - Quenched and Tempered. Fatigue rated at 1-1/2 times the Working Load Limit at 20,000 cycles All Bolts Hot Dip galvanized after threading (UNC). Furnished with standard Hot Dip galvanized hex nuts. Recommended for in line pull. Crosby products meet or exceed all the requirements of ASME B30. 26 including identification, ductility, design factor, proof load and temperature requirements. Importantly, Crosby products meet other critical performance requirements inluding fatigue life, impact properties and material traceability, not addressed by ASME B30. 26.