Of all the components composing a machine tool, the base is one of the most important parts. It not only props up the weight of all the other components but also withstands the cutting force of processing. The subjects of this study are two grinders; although the aim of their use is slightly different, the structures of the two grinders are very similar. The main variation is the base; cast iron material is used in one base while the other is cast from mineral resin. This study focuses on the similarity of the structures and the differences in dynamic response characteristics caused by different materials. Experimental results showed that possible structural blemishes exist in the mineral resin base in the lower frequency range, and the dynamic characteristics of a mineral resin grinder are worse than those of a cast iron grinder. However, in the frequency range under discussion, the mineral resin grinder is less likely to cause resonance.