A worm gear consists of two main parts - a worm and a gear. Similar to a ball screw, worm gears
can have multiple threads, which make them suitable for either single or multiple starts. When a single-start worm makes a 360-degree full turn, it will move to one tooth. For example, if it has 30 teeth, the gear reduction will be 30:1. On the other hand, multi-start worm's gear reduction is a result of the gear's number of teeth. Then, divided by its number of starts. Since its reduction ratio is dependent on the number of teeth, worm gears are perfect for speed reduction and applications such as lifting and hoisting while keeping silent. Its construction and configuration also make them compact and great for meshing.