ARP Main Studs are manufactured from 8740 chome moly steel, heat-treated in house for 200,000 psi tensile strength and precision J-formed threads rolled after heat treatment to create a fastener that has threads 1000% stronger than OEM equipment. This kit comes complete with hardened parallel-gound washers and aerospace quality nuts. This kit can help to reduce crankshaft flex and main cap fretting with these more durable, stronger fasteners.This kit has all hardware for a complete main bolt to stud conversion.