One of the most common approaches to creating ultrafine materials is ball milling. Among the various types of ball mills, planetary ball mills are widely used by the research community. A planetary type ball mill is economical, simple to operate, and ideally suited for small-quantity batch type synthesis of powders and alloys and for reactive processing of powders. The size of the jar and balls, rotational speed, milling duration, ball-to-powder ratio, jar material, milled material, and temperature are the most important process factors in ball milling. Temperature was determined with the help of non-contact temperature measuring device. The rate of grain size reduction and the minimum grain size that can be achieved for a given powder material depend on the above parameters. A huge number of tests would be needed to find the optimal values for the approximately ten process parameters with interaction effects. As part of this research effort, a Taguchi Design of Experiments (DOE) approach was adopted to determine the optimum process parameters to obtain the fine grain sizes for iron, cobalt, and nickel powders. Although the ball-to-powder ratio and ball milling time each have around a 20–25% impact on the grain size reduction rate, ball milling speed has almost a 48% impact. The powders were characterised for grain size using an x-ray diffraction technique, and the powder morphology was studied using a scanning electron microscope.