Spiral bevel gears are usually made from hardened steel. The teeth of these gears are often ground for a far more precise finish allowing for little noise at high speeds. You can specify left hand or right hand depending on the direction you should run the gears
If you have a higher speed spiral gear china application that will require a lot of torque after that spiral bevel gears are a great option. The gears operate at 90° to one another and have “spiral” shaped tooth which provides maximum tooth surface contact while rotating. With get in touch with spread over the complete tooth the spiral bevel gear could be run much faster compared to the straight tooth bevel gear and handle harder starts 
and stops.
We make spiral bevel gears only for industrial applications.
Worm gears are used in large equipment reductions. Gear ratio ranges of 5:1 to 300:1 are usual. The setup is designed to ensure that the worm can turn the gear, however the gear cannot change the worm. The position of the worm is definitely shallow and consequently the gear is held set up because of the friction between the two. The equipment is situated in applications such as conveyor systems where the locking feature can act as a brake or a crisis stop.
The model cross-section shows a typical placement and utilization of a worm gear. Worm gears have an inherent protection mechanism built-in to its style since they cannot function in the invert direction.