Arp Has Developed An Innovative Multi-purpose Accessory Stud That Can Be Used For Exhaust Systems, Intake Manifold And A Host Of Other Uses. The Studs Are Manufactured From A Proprietary Alloy Developed By Arp (stainless 300) And Are Impervious To The Rust And Corrosion That Plagues Ordinary Fasteners. This Stainless Steel Alloy Is Norminally Rated At 170,000 Psi Tensile Strength, Which Is Substantially Stronger Than Grade 8 Hardware. Ideally Suited For Installing Exhaust Headers, The 8mm Studs Have A Unique Nut Starter Nosie And A Hex-broached Tip, Which Allows The Studs To Easily Be Installed Using An Allen Key. The Studs Come With Easy Wrenching 12-point Nuts, Which Work Great In The Tightest Of Quarters. Flat Washers Are Also Included.