PURPOSE: To easily measure the parallelism accuracy of each grinding part and the step difference accuracy between the grinding parts of a stepped grinding wheel having plural grinding parts for simultaneously grinding plural cylindrical parts with step difference.
CONSTITUTION: A swivel base 14 turnable around a Z-axis is provided on a movable base movable at least in the direction of a Y-axis of an X-Y-Z triaxial orthogonal coordinate system. A test piece P having ground parts Pa, PB corresponding to each grinding part, ground by a stepped grinding wheel is set onto the swivel base 14 through a jig 15. The X-axis direction positions of the ground parts Pa, Pb are measured by displacement gauges 171, 172, and the test piece P is turned through the swivel base 14 so that the step difference dimension (d) in the X-axis direction of the measured parts is the specified value. The test piece P is then moved in the Y-axis direction by the movement of the movable base while measuring the X-axis direction positions of the ground parts so as to measure the parallelism of the ground parts to the Y-axis.
MORI KAZUO
KITAHARA OSAMU
