12-Point Engine Fastener KitExhaust studs/lock nuts kit (includes 12-point heat-treated 8740 chrome moly steel bolts with black oxide finish) Precision rolled threads for optimum engagement, to prevent galling and promote consistent torque loading Wide underhead flange design provides even load distribution for sealing of surfaces to prevent leaks Tensile strength rated @170,000 psi - superior and stronger than OEM & grade 8 fasteners Manufactured by ARP® to Feuling’s® exact specifications All kits include moly assembly lubricant for installation Made in the U.S.A.