The bimetallic method is expedient from an economic point of view. Bronze is a fairly expensive non-ferrous metal due to its performance properties, high hardness and good ductility during processing. However, in this area in its pure form it is used quite rarely. If the wheel will be used in low-speed, low-performance units, it is quite possible to create parts by centrifugal casting using a cast iron core. There are also cases. When such an element is entirely made of gray cast iron. But it is the bronze worm wheels that are considered the most efficient and reliable.
The bronze worm gear is able to transmit torque as accurately as possible, which also indicates improved technical characteristics. Its production is preceded by a tedious calculation process at the design stage, which additionally increases the cost of worm gears made of this metal.