The manufacturing methods of worms are roughly divided among cutting, heat treated and ground after cutting and rolling. And for worm wheels, they could be approximately divided among cutting teeth, cutting teeth after casting, and pearly whites cutting after the exterior rim is usually cast around the guts of the blank.
As for the supplies for worm gears, for worms: structural carbon steel (S45C, etc.), structural alloy steel (SCM415, etc.), stainless and cast iron will be used; and for worm wheels: cast iron (FC200, etc.), non-ferrous metals such as plastic worm gear phosphor bronze and specialty bronze (nickel bronze, aluminum bronze, etc.), engineering plastics such as for example MC Nylon, etc. Because the combination of resources for worms and worm wheels affects the allowable transmission induce and lubrication methods, the decision of mating materials requires consideration. Also, related to the friction of tooth, a harder material for worm than worm steering wheel is generally used.
Ordinarily the lead angles of the right and left tooth surface of a worm will be the same. Yet, in duplex worm gears, they are made to ensure that the tooth thickness of the worm improvements continuously in the axial course so that by shifting the worm 
axially with shims, it turns into possible to adapt the backlash.
If a worm gear is used, a big speed decrease can be obtained in a compact space compared to using spur gears. Generally, the worm is employed to turn the worm steering wheel. However when the lead angle is especially small, the worm wheel cannot turn the worm and it is named its self locking characteristic. This works extremely well effectively in some applications but it can’t be called ideal preventative for reverse driving. (When the business lead angle is certainly large, it is possible to switch the worm with the worm wheel.) Furthermore, there are many advantages to worm gears such as for example low noise and vibration, but due to the large sliding at the tooth areas (sliding contact), the efficiency is usually low. (For cylindrical worm gears, the overall efficiency is about 30-90%.) Likewise, there are drawbacks such as for example they tend to have problems with tooth surface heat seizure.
