Bolt sets contain 6 bolts with tapered heads and 6 flanged nylon lock nuts. We recommend replacing your sprocket bolts at the same time you replace your rear sprocket. The old bolts are often stretched or stripped, while used lock nuts are more likely to come loose. This can result in wheel hub and swing arm damage which can be very expensive to repair as many a sorry rider can attest to.Manufactured from Grade 12.9 high strength steel.Chromed surface for anti-corrosion.Large M8 socket head for easy installation.Flanged nuts feature nylon lock ring to prevent nut and bolt coming loose