These 5/16-18 x 1 ARP grade 8 stainless steel header bolts are not affected by corrosion or extreme heat. These bolts are rated at 170,000 psi and come with a polished finish. They have a 3/8 12 point hex head and a .620 flange so they will fit in close to the header tube. This is a set of 12 bolts. Please click here to see a larger image.