Description All tolerances +/- .13mm May also be available in other materials. Metric Flat Washers Variations Description OD ID THK Quote M2 5 2.15 0.8 M2.5 5.6 2.65 0.8 M3 8 3.2 0.8 M3.5 8 3.7 0.8 M4 9 4.3 0.8 M5 11 5.3 1 M6 12 6.4 1.5 M8 18 8.4 2 M8.5 25 8.5 2 M10 22 10.5 2.5 M12 25.14 13.43 2.53 M12 33.64 13.4 3.06