The steel is used for high strength worm gears (worm wheel) and steel may be plain carbon steel or alloy steel. The steel gears are usually heat treated so as to combine effectively the toughness and tooth hardness.
The phosphor bronze is widely used for worms drive in order to reduce wear of the worms which is excessive with cast iron or steel.
Worm gear sets are usually used to lessen speed and increase torque. Because the worm travel undergoes more 
contact pressure cycles than the worm equipment, the worm travel is often of a more robust material.
• Cast iron provides durability and simple manufacture.
• Cast steel provides less difficult fabrication, strong doing work loads and vibration level of resistance.
• Carbon steels are inexpensive and strong, but are vunerable to corrosion.
• Aluminum is utilized when low gear inertia with some resiliency is necessary.
• Brass is inexpensive, easy to mold and corrosion tolerant.
• Copper is easily shaped, conductive and corrosion resistant. The gear’s durability would enhance if bronzed.
• Plastic is inexpensive, corrosion resistant, calm operationally and will overcome missing teeth or misalignment. Plastic-type is a smaller amount robust than steel and is susceptible to temperature adjustments and chemical corrosion. Acetal, delrin, nylon, and polycarbonate plastics are common.
This 27 tooth brass worm gear will be used with a worm gear to create a 27:1 reduction in speed while also changing the orientation of the rotating axis by 90 degrees. This gear fastens to a 1/4″ shaft utilizing a specialized 1/4″ D-hub to be utilized with 1/4″ D-shaft.
The manufacturing ways of worms are roughly divided among cutting, heat treated and ground after cutting and rolling. And for worm wheels, they may be roughly divided among cutting teeth, cutting the teeth after casting, and pearly whites cutting after the outside rim is definitely cast around the center of the blank.