The current industry standard, these 20° pressure angle gears have thicker, stronger teeth than 14½° pressure angle gears. They're also known as spur gears.

With straight, conically shaped teeth and a 1:1 speed ratio, miter gears connect two shafts at a right angle without changing shaft speed or torque. They're more efficient than spiral miter gears because they create less friction.

Also known as spiral miter gears, these gears have curved teeth that gradually engage and stay in contact longer than straight teeth so they handle heavier loads at higher speeds. Speed ratio is 1:1.

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.