Titanium bicycle hexagon socket crank bottom bracket bolt screw. Made from titanium alloy,high strength,strong, lightweight, rust-proof, corrosion-resistant, wear-resistant and durable. Easy to install and convenient to use. Great ability to withstand high and low temperatures. Great replacement accessories for your bicycle, motorcycle modification. Specification: Material: Titanium Alloy Size: M6x35, M6x40, M6x45, M6x50, M6x55, for you choose Color:Titanium Size Chart: Size 1: M6x35 Overall Length: Approx.41mm/1.6 inch Thread Length: Approx. 35mm/1.4 inch Diameter: Approx. 6 mm/0.24 inch Size 2: M6x40 Overall Length: Approx.46mm/1.8inch Thread Length: Approx. 40mm/1.5 inch Diameter: Approx. 6 mm/0.24 inch Size 3: M6x45 Overall Length: Approx.51mm/2.0 inch Thread Length: Approx. 45mm/1.8 inch Diameter: Approx. 6 mm/0.24 inch Size 4: M6x50 Overall Length: Approx.56mm/2.2 inch Thread Length: Approx. 50mm/1.97 inch Diameter: Approx. 6 mm/0.24 inch Size 5: M6x55 Overall Length: Approx.61mm/2.4inch Thread Length: Approx. 55mm/2.2 inch Diameter: Approx. 6 mm/0.24 inch Package Includes: 1 Piece Bracket Bolt Screw Note: Please allow slightly difference due to manual measurement.Color may be slightly different since different monitor. Thanks!