In the process of metallographic sample preparation, sample grinding is an indispensable process. Sample grinding is generally divided into two processes: rough grinding and fine grinding. The purpose of rough grinding is to obtain a flat surface, which is generally completed on a grinding wheel machine. There are still deep marks on the surface of the sample. The purpose of fine grinding is to eliminate these grinding marks to obtain a flat and smooth grinding surface to prepare for the next step of polishing. The M-2 Metallographic Sample Pre-Grinding Machine can be used for fine grinding of metallographic samples. It has a double-disc design and can be operated by two people at the same time. The shell adopts overall blister technology, with a novel appearance, stable rotation, low noise, easy operation, high work efficiency, etc. It also has a built-in cooling device, which can cool the sample during grinding and polishing to prevent the metallographic structure from being damaged due to overheating of the sample. It is suitable for metallographic laboratories in factories, colleges and universities, and scientific research institutions. It is an excellent equipment for pre-grinding metallographic samples.