Using test specimens cut or cuts, when scribing blade cutter position adjustment, improve the way symmetry is primarily to improve the measurement accuracy of turn key rollover test method degree of symmetry. In addition to the exact angle of rotation of the workpiece, the workpiece to improve the measurement accuracy of the position, but when using the key indicator measuring side, taking into account the impact of the machine work surface roughness and flatness and flatness of the opposite side of the amount of precision, accuracy can be placed in a countertop higher parallel pad, move the indicator measuring the seat pad on the plane, in order to improve the measurement accuracy of the adjustment process. When the error trace symmetrical lateral adjustment of the table, in order to improve the accuracy of the table trace movement can be controlled by means of the instruction sheet.