Roundness is a measure of how close an object's shape is to a mathematically perfect circle. Roundness applies in two dimensions, such as the circle along the cross-section of a cylindrical object such as the shaft of a bearing or a cylindrical roller. In geometric dimensioning and tolerancing, the

According to the condition of the workpiece during the measurement process, the roundness meter can be divided into two types: workpiece rotating type and workpiece stationary type.