These plastic gears are lighter and quieter than metal gears—pair them with metal worms for lubrication-free operation. Worm gears use screw threads to make large reductions to shaft speed while transmitting motion at a right angle. They transmit motion from worm to gear and cannot be reversed. For gears and worms to mesh correctly, they must have the same pressure angle, pitch/module, number of thread starts, and thread direction.

Speed ratio is the ratio by which output shaft speed is reduced. As speed decreases, torque increases.

Acetal gears are lightweight, and resist corrosion and chemicals. They absorb less moisture than nylon gears, so they’re less prone to dimensional changes. They’re best suited for light duty applications, such as prototyping.

Nylon gears are lightweight and stronger than acetal gears.

For technical drawings and 3-D models, click on a part number.