Essential for high performance engine builds, heavy duty head studs reduce cylinder head movement in high boost or high compression engines optimizing cylinder head to block sealing. Cosworth Ultra High Performance Head Studs are manufactured from H11 tool steel with 260,000psi tensile strength and come complete with nuts and washers. Manufactured with hex broach end for ease of installation. Additionally, genuine Cosworth head studs utilize a base seating feature to evenly distribute maximum load on the stud and not the threads. This feature is typically found only in high level race engines.