ARP Main Stud kit for Commonblock engines help eliminate main cap walk. The studs are manufactured using the best materials, processes, designs and engineering. Every main stud kit exceeds the most stringent aerospace specifications. All kits come complete with hardened parallel-ground washers and aerospace quality nuts. The studs are manufactured from 8740 chrome moly steel, heat-treated to 190,000 psi tensile strength, and precision J-form threads rolled after heat-treat to create a fastener that has threads 1000% stronger than other brands.