Premium Grade Bolt And Stud Kits To Facilitate Installation Of Exhaust Headers. The Stainless 300 Material Is Not Affected By Corrosion Or Extreme Heat. Compact 12-point Design Lets You Easily Slip A Socket Close To The Pipe. Kits Include Specific Number Of Parts For Your Application, Premium Grade Washers And Hex Or 12 Point Nuts. Studs Are Manufactured With A Unique Nut Starter Nose That Helps Prevent Cross Threading. Studs And Bolts Come In Either Black Oxide Chrome Moly Or Stainless 300, Both Are Rated At 170,000 Psi.