ARP studs are rated at 220,000 psi tensile strength, and provide the clamping force required to keep cylinder heads from lifting due to higher combustion pressures. Made of proprietary ARP 2000 material, with threads rolled after heat-treat to provide optimum fatigue strength. The ends of the studs are broached to facilitate easy installation. This feature also enables the cylinder head to be removed in tight quarters. Included in each kit are heat-treated, chrome-moly steel 12-point nuts and parallel-ground washers. All parts have a black oxide finished for extra durability.