Martin TS2020BS 1/2 Spur Gear, 20&deg; Pressure Angle, High Carbon Steel, Inch, 20 Pitch, 1/2" Bore, 1.1" OD, 0.500" Face Width, 20 Teeth Transmits torque between parallel shafts to provide rotational power to another part of a motorized system Pressure angle of 20 degrees for a lower contact ratio between gears, resulting in higher load capacity than smaller pressure angles Diametral pitch of 20 for applications requiring a balance between transferring torque and controlling changes in speed and direction of rotation with precision High carbon steel for tensile strength and hardness