The original imported QATM automatic vertical metallographic pre grinding machine SAPHIR 375 from Germany adopts central pressure and has automatic sample grinding monitoring function, especially suitable for precision rough grinding of metallographic samples. The grinding disc can be automatically or regularly repaired. The circulating cooling system is integrated into an aluminum modular structure, which is compact and convenient to use. The SAPHIR 375 can use aluminum oxide grinding discs or diamond grinding discs, and therefore has different configurations. The diameter of the working disc is 350 mm. The grinding process is initiated by manual control, and is completed in a fully enclosed environment. The safety sensor can avoid grinding without placing the sample on the grinding plate. Before installing the grinding disc, the grinding process cannot be started. It is a safe and reliable fast metallographic pre grinding machine.