A plastic gear tooth greatly deflects because of low mechanical strength. This causes a delay in rotation to the mating driven gear (steel gear) and allows the root of the tooth of the plastic gear to be scooped out by the addendum edge of the steel gear when the succeeding teeth mesh with each other. We have already proposed several methods to prevent this. Apart from these methods, however, we have worked out a way to avoid using a plastic gear made from low friction coefficient materials. We have manufactured gear from two types of low friction coefficient materials of nylon obtained by charging super high molecular polyethylene and synthetic wax, and performed an operation test and studied its effect.