The difference between the traditional ball or cylinder shaped and the cuboid shaped grinding blocks is that the former is by point contact or linear contact, and the latter is by planar contact.

• 球形、圆柱形研磨体与长方体研磨体的区别在于，前者是点接触和线接触，后者是在长方体的基础上对各边及角度进行修正后形成的，研磨体间是面接触。