Worm gears are used when large gear reductions are needed. It’s quite common for worm gears to have reductions of 20:1, and also up to 300:1 or greater.
Many worm gears have a fascinating property that no additional gear set has: the worm can simply turn the gear, but the gear cannot turn the worm. This is because the position on the worm is indeed shallow that when the gear tries to spin it, the friction between the equipment and the worm keeps the worm set up.
This feature is useful for machines such as conveyor systems, in which the locking feature can act as a brake for the conveyor when the motor is not turning. 
One other very interesting utilization of worm gears is definitely in the Torsen differential, which is utilized on some high-performance cars and trucks.
PRODUCT INTRODUCTION:
MAIN FEATURES:
1) Made of high quality aluminum alloy, light weight and non-rusting
2) Large output torque and high radiating efficiency 3) Smooth running and low noise, can work long time in dreadful condition
4) Good-looking appearance, durable service life and small volume
5) Suitable for omnibearing installation
MAIN MATERIALS:
1)housing: aluminium alloy ADC12(size 025-090); die cast iron HT200(size 110-150);
2)Worm:20Cr, ZI Involute profile; carbonize&quencher heat treatment make gear surface hardness up to 56-62 HRC; After precision grinding, carburization layer’s thickness between 0.3-0.5mm.
3)Worm Wheel:wearable stannum alloy CuSn10-1
We started our business from 1995 and now we are the one of the leader manufacturer of power transmission products. It worm gear focuses mainly on Keyless Locking Devices, Timing Belt Pulleys, Roller Chains, Bearing, Jaw Couplings, Gears and other parts.
These products are produced in conformity with the International Standard and the standards adopted in industrialized countries (DIN ANSI BS JIS) with up to data equipment, advanced technology and perfect management system for quality control. It boasts a team with rich experience in this industry, focusing on global market. So the products are of good quality with competitive prices.