All Pro Series bolts are cold-forged to ensure molecular integrity, heat-treated prior to thread rolling and machining, and are rated nominally at 200,000 psi. ARP Pro Series head bolt kits are application specific - designed for use with typically competition only components.

All Pro Series bolts are cold-forged to ensure molecular integrity, heat-treated prior to thread rolling and machining, and are rated nominally at 200,000 psi. ARP Pro Series head bolt kits are application specific - designed for use with typically competition only components.

ARP uses a premium grade 8740 alloy that is rated far superior to "aircraft" quality. Then, each stud is placed vertically in special racks and precisely heat-treated to 200,000 psi.

ARP uses a premium grade 8740 alloy that is rated far superior to "aircraft" quality. Then, each stud is placed vertically in special racks and precisely heat-treated to 200,000 psi.

ARP uses a premium grade 8740 alloy that is rated far superior to "aircraft" quality. Then, each stud is placed vertically in special racks and precisely heat-treated to 200,000 psi.

ARP uses a premium grade 8740 alloy that is rated far superior to "aircraft" quality. Then, each stud is placed vertically in special racks and precisely heat-treated to 200,000 psi.

ARP Uses A Premium Grade 8740 Alloy That Is Rated Far Superior To Aircraft Quality. Then Each Stud Is Placed Vertically In Special Racks And Precisely Heat Treated To 200,000 Psi.

General Motors 2.2L Ecotec, 12-point nuts and under cut studs, ARP Head Studs 231-4701ARP Head Stud Kits with 12-point Nuts and Under Cut Studs .