Stainless steel motorcycle bolts: Made of 316 stainless steel, which gives superior strength and resistance to corrosion, we are proud to offer an exceptional quality product. Pro-Bolt is the first to offer BTR stainless steel tapered head bolts, domed head bolts and countersunk head bolts in stainless steel. We offer a unique material in unique head styles for a mirror finish. Stainless steels are iron alloys with a minimum of 10.5% chromium, and other elements added (nickel, molybdenum, titanium, copper, carbon, nitrogen) to improve properties such as strength and formability. A chromium-rich oxide film in stainless steel gives its corrosion resistance.