The current industry standard, gears with a 20° pressure angle have thicker, stronger teeth than gears with a 14½° pressure angle.

Transmitting loads at higher speeds than spur gears in environments where rusting and exposure to chemicals is a concern, these plastic gears have helical teeth, which stay in contact longer than straight teeth. They’re often called screw or crossed-helical gears.

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.