The Martin double, also known as a duplex, type B sprocket is suitable for use with the series 60-2 chain with 3/4” pitch for driver or driven sprocket applications. Varying numbers of teeth and pitch diameters offer application flexibility. Made from high carbon steel, it has high strength and durability. Multiple chain capability allows for more power at higher operational speeds with greater load capacity. Type B sprockets have a hub extension on one side to provide stability, and allow for the use of full-depth keyways and standard setscrews to attach the sprocket. They can also accommodate a wide range of shafts. The double style accepts two chains side–by-side. The options for this class of sprocket are: number of teeth from 11 to 95; outside diameter from 3.000 to 23.120”; stock bore size from 1 to 1-1/4”; maximum bore size from 1-1/4 to 3-3/4”; hub diameter from 1-13/16 to 5-1/2”; length through bore from 2-1/8 to 3-1/2”; and approximate weight from 1.62 to 87.14 lb. The face width (not including the hub) is 1.341”. The chain row thickness is 0.444” nominal. Maximum bores will accommodate standard keyseat and setscrew over keyseat. Slightly larger bores are possible with no keyseat, shallow keyseat, or setscrew at angle to keyseat. All Martin sprockets meet or exceed ANSI standards. A sprocket is a wheel with teeth around the perimeter that meshes with a chain, track, or other perforated or indented material. Unlike gears that mesh with another gear, sprockets mesh with a chain, which then interacts with another sprocket. Gears can be used to transmit power around a corner, based on how they fit together. Sprockets with chains only work in straight lines. Some common benefits of chain-drive systems include minimal slippage, a fixed ratio between rotating shafts, and versatility with many different chain attachments and sprocket material selections. An example of a power transmission system is a standard bicycle, which has a sprocket and a chain to deliver power from the rider’s legs to the wheels making the bike move. Martin Sprocket & Gear manufactures power transmission and conveying products. The company was founded in 1951 and is headquartered in Arlington, TX. Martin provides tools that meet American National Standards Institute (ANSI), National Aerospace Standard (NAS), and Deutsches Institut für Normung (DIN) standards.