ARP 208-4301 M10 Cylinder Head Studs Kit for 1988-1995 Honda D16Z D16A6 D16Z6 EnginesFastener Style: Stud Undercut Stud: No Head Style: 12mm 12 point Fastener Material: 8740 chromoly Fastener Finish: Black oxide Washers Included: Yes Pro series cylinder head studs from ARP are cold forged to ensure molecular integrity. They are heat treated prior to thread rolling and machining and are rated at a whopping 220,000 psi. ARP Pro series kits are also available with 12 point nuts, and all kits come complete with hardened parallel washers