Obtaining optimum cylinder head-to-block sealing is especially critical in small displacement engines using high comp pistons or power adders like turbochargers, nitrous oxide and superchargers.

ARP uses premium grade 8740 alloy that is rated far superior to “aircraft” quality. Each stud is precisely heat-treated to 200,000 psi. Following heat-treat, each stud is centerless ground to make it as close to perfectly concentric as possible. This involves about ten very slight cuts and results in an exceptionally straight part (lesser quality studs are not even centerless ground – the material is thread rolled in bar stock form, usually prior to heat-treat). Because ARP studs are manufactured to such exacting tolerances, gaskets and cylinder heads literally glide into position and are perfectly aligned – something that won’t happen with inferior quality head studs.

ARP studs are thread rolled after heat-treat, which gives them about 1000% (that’s ten times), better fatigue strength than those studs that are threaded prior to heat-treat.