Vertical spindle double disc surface grinders are provided with two pieces of grinding wheels as a pair and a rotary carrier disc to feed workpieces into the machine. It is widely used for grinding of small dimensions of ceramic components like alumina components, sintered ferrite magnets, NdFeB magnets, SmCo magnets, etc. in the ceramic or in the magnet mfg. industries. As a recent trend of its applications, the machine is used for plastic magnets like bonded NdFeB ring magnets for HDD motors which require high dimensional accuracies. The upper grinding spindle can be easily swung to the side of machine, thus the checking or the replacement of grinding wheels are facilitated.