Milling cutters are rotating cutters used in machining applications. Common configurations include end mills, face mills, shell mills, and application-specific cutters and geometries.
Ratchets and pawls are mechanical gearing used to transmit intermittent rotary motion. They permit a shaft to rotate in one direction, but not in the opposite one.
Worm gears are cylindrical gears with a spiral thread that drive mating worm wheels in high-reduction gearset applications. They operate on non-intersecting perpendicular axes.