Plastic helical gears are widely used, the teeth are cut at an angle. The meshing between a helical gear and a worm is quieter and smoother than spur gears since the teeth on helical gears are specially cut at an angle so when two teeth on the gear system engage, it starts a contact on one end of the tooth which gradually spreads with the gear rotation, until the time when both the tooth are fully engaged.
Properties of nylon gears
Other colors and sizes of helical gear are available
