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. These worms are compatible with plastic worm gears.

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

1045 carbon steel worms have rolled threads. Hardened 1045 carbon steel worms have ground threads, which are more durable and precise than rolled threads.

303 stainless steel worms won’t rust in wet environments, so they’re commonly used in food-processing plants and other areas with frequent cleaning.

4140 alloy steel worms are already mounted on a shaft, so they’re ready to use with no machining required. The threads are ground into the shaft for higher precision than rolled threads, and hardened for additional durability and precision.

Cast iron gears are strong and durable.

Bronze gears have low friction and dissipate heat better than cast iron gears to provide a long service life for both the gear and the worm. They’re also more corrosion resistant than cast iron gears.

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