ARP uses premium grade 8740 alloy that is rated far superior to that of supposed "aircraft" quality. Each ARP bolt is precisely heat-treated to 200,000 psi and is center-less ground for an exceptionally close to concentric part. The ARP high tensile strength stud sets are superior to OEM head bolts and can be reused unlike factory stretch hardware. Obtaining the optimum cylinder head-to-block sealing is critical in small displacement engines employing high compression pistons or engines that utilize forced induction like a turbo or supercharger.
All bolts are precision centerless-ground and thread-rolled to Mil-S-8879 specs. Each utilizes a black oxide finish that protects them from wear and corrosion. We even throw in hardened parallel washers for uniform load distribution and accurate torque readings.
