Printing machine dedicated DC reducer electric motor in mechanical and electrical industry is a relatively common miniature reducer motor, but now for the performance and materials of the reducer motor and how manufacturers choose materials etc. the comparative expertise knowledge should not be too much, and not a day or two can be understood, mainly from: considering the magnetic field nature, considering the various gear reducer motor to the impulse iron core magnetic conductivity directionality and uniformity cold rolling, considering the reducer motor iron core working magnetic density high and low, considering the iron heart loss size and other aspects to start.