Metal casting surface polishing flatness detection tool

The utility model discloses a metal casting part surface polishing flatness detection tool, and relates to the technical field of flatness detection, the metal casting part surface polishing flatness detection tool comprises a bottom plate, the left end of the upper surface of the bottom plate is fixedly connected with a U-shaped groove body, the right end of the upper surface of the bottom plate is provided with a guide assembly, the opposite inner side walls of the U-shaped groove body are provided with sliding grooves, and the inner surfaces of the sliding grooves are slidably connected with sliding plates; positioning assemblies are installed at the two ends of the upper surface of the sliding plate, a metal casting part body is placed between the two positioning assemblies, a fluctuation sensor is fixedly installed at the upper end of the inner wall of one side of the left end of the U-shaped groove body, the output end of the fluctuation sensor is connected with a detection wire harness, and the end, aw