ARP Main Stud Kit 12PT Nut suit Mazda 1.6L B6 & 1.8L BP DOHC Miata ARP main stud kits are made from 8740 chromoly steel and have a 190,000 psi tensile-strength rating. They are precision centerless-ground and thread-rolled to Mil-S-8879 specs, with a black oxide finish for corrosion resistance. The kits come complete with hardened washers and high-strength hex nuts. Elevate your Mazda 1.6L B6 & 1.8L BP DOHC Miata's engine performance to the next level with the ARP Main Stud Kit 12PT Nut. Made from 8740 chromoly steel and boasting a 190,000 psi tensile-strength rating, these main stud kits are built to withstand extreme pressure and ensure maximum stability for your engine. With precision centerless-ground and thread-rolled construction to Mil-S-8879 specs, along with a corrosion-resistant black oxide finish, you can trust in the quality and durability of these kits. And to top it off, they come complete with hardened washers and high-strength hex nuts for a comprehensive engine upgrade. Give your Mazda the boost it deserves with ARP Main Stud Kits.