Boston Gear NH18B Spur Gear, 14.5 Pressure Angle, Steel, Inch, 8 Pitch, 0.875" Bore, 2.500" OD, 1.250" Face Width, 18 Teeth Transmits torque between parallel shafts to provide rotational power to another part of a motorized system Pressure angle of 14.5 degrees for a higher contact ratio between gears, resulting in quieter operation than larger pressure angles Diametral pitch of 8 for applications where transferring torque is more important than controlling changes in speed and direction of rotation with precision Low carbon steel (.2 percent carbon) for applications where the hardness and strength of higher levels of carbon are not needed to transmit torque and motion