Clamping thread (M): M12 Grid pitch (R): 40 mm ± 0.01 mm Grid hole (D): Ø 16F7 Grid hole (E): 12 mm Perpendicularity: 0.01/200 mm Clamping surface face: smoothed after nitration Hardness: 700-100 HV1 Material: case-hardened steel Alignment hole and centre hole: with hardened bushes in accordance with DIN 179 with base surface Base surface: with hole pattern according to table or drawing, suitable for machine table in accordance with DIN 55201