SR20DET Head Bolts
ARP uses a premium grade 8740 alloy that is rated far superior to “aircraft” quality. Each ARP stud is placed vertically in special racks and precisely heat-treated to 200,000 psi.
Each ARP stud is centerless ground to make it as close to perfectly concentric as possible. This procedure involves about ten very slight cuts and results in an exceptionally straight part.
http://store.drifting.com/arp/arp_head_stud/bolt_kits/1024701/i-61507.aspx
