This is a grade 8 stainless stud and nut kit for the 39-48 Ford Flathead stock exhaust manifolds. Included in the kit are 12 studs, 12 flange nuts, and 12 washers. These grade 8 studs will withstand the high temperatures on the exhaust manifolds. These studs are much stronger than the stock bolts and are rated at 170,000 psi. They also have a polished finish on them.