ARP's Main Bolts are far superior to any other main bolts available, for use in both street or competition, designed to meet the exacting standards and demands of professional engine builders. Forged from 8740 chrome moly steel, all main bolts feature a reduced wrenching head, large underhead radius and rolled threads for the utmost in reliability. The threads are rolled after heat-treating which gives them about 2000% better fatigue strength than most main bolts that are threaded prior to heat-treating. Hardened parallel-ground washers are included with each kit. Also available in Main Studs.