Matex uses several different materials in our low-cost plastic planetary gears. The outer ring gear is constructed entirely out of plastic while the inner planets and rollers are made of sintered metal. Carrier plates are usually made of ZDC2 but can be made in a variety of materials (from sintered metal to steel) when higher loads demand a more robust material. This combination of materials allows Matex Products to drastically cut weight and noise while still providing the strength required to handle those higher torque applications that an all plastic planetary gear system could not sustain.