These reusable heat treated 8640 steel bolts have a 200,000 psi Ultimate Tensile Strength, 14% stronger than stock. They feature a durable Black Oxide coating, 9/16" 12-point heads with integral washer, formed threads and cold formed heads. Also available including 4140 Chrome Moly tempered steel cylinder studs with 180.000 PSI tensile strength. Fits all 2017 to present Milwaukee Eight engines.