pm of a ball mill,Planetary Ball Mill PM 100 - RETSCH - highest finenessPlanetary Ball Mills are used wherever the highest degree of fineness is required. Powerful and quick grinding down to nano range. Read more.pm of a ball mill,Planetary Ball Mill PM 200 - RETSCH - short grinding timesThe Planetary Ball Mill PM 200 is an excellent choice when a high degree of fineness is required. Grinding down to the nano range. Read more.