ARP main studs are manufactured from 8740 chrome moly steel, heat-treated in-house to 200,000 psi tensile strength, and precision J-form threads rolled after heat-treat to create a fastener that has threads 1000% stronger than others. All kits come complete with hardened parallel-ground washers and aerospace quality nuts. Reduce crankshaft flex and main cap fretting with these premium quality main studs. Don't settle for anything less than the best!