A dual lead worm and worm wheel is a type of gear system used for power transmission. It consists of a worm, which is a screw-like cylindrical component with helical teeth, and a worm wheel, which is a gear with teeth that mesh with the worm.

The term "dual lead" refers to the fact that the worm has two sets of teeth, or threads, that wrap around the cylinder at different angles. This design provides a higher gear ratio compared to a single lead worm, which means that the worm wheel will rotate more times per revolution of the worm.

The advantage of using a dual lead worm and worm wheel is that it can achieve a large gear ratio in a compact design, making it useful in applications where space is limited. It is also self-locking, meaning that the worm can hold the worm wheel in place without the need for a brake or other locking mechanism.

Dual lead worm and worm wheel systems are commonly used in machinery and equipment such as conveyor systems, lifting equipment, and machine tools.