To provide a stone mill capable of easily enhancing processing accuracy of a rotation mechanism, having small discrepancy of a rotating axis and small dispersion of the gaps of a sliding surface, and enhancing compatibility with various stonemills having different ditch shapes of the sliding surface. 回転機構の加工精度を容易に高めることができ、回転軸のずれ、摺接面の間隔ばらつきが少なく、摺接面の溝の形状の異なる種々の石臼との互換性を高めることができ石臼を得る。 - 特許庁