The teeth can be either helical or spur. In an involute-form, the internal gear teeth have a concave rather convex design with a thicker base than an equivalent external gear. These gears not only give greater tooth strength but because of a lower sliding velocity along the tooth profile, makes these gears quieter. We offer precision engineered internal gears that have found variety of uses and applications in rollers, indexing, timing and other light duty applications. Internal gears are used as tools for creating solid models of drive components. These gears have cylindrical pith surface with a teeth, which is parallel to the axis.