Harley Davidson Seat Bolt Black Billet Aluminum Hard Anodized by FGT Motorsport CNC machined from solid billet aluminum grade 6061-T6 Neoprene washer bonded to corrosion resistant 18-8 stainless steel protects your beautiful chrome and makes for a secure fit Seat bolt is hard anodized black to Mil Standard MIL-A-8625 with minimum surface hardness of Rockwell C75 and will not rust or flake Type 18-8 corrosion resistant stainless steel threads Thread type is 1/4"-20. Please check the existing thread type on your Harley Seat Bolt first to confirm that this product will be compatible. A very small number of Harley models use 1/4"-28 which won't work with this seat bolt.