Spherical Washer Bottom Washer Inside Diameter 9.6 mm Bottom Washer Outside Diameter 17 mm Bottom Washer Radius 12 mm Finish Plain For Screw Size M8 Material Stainless Steel Material Grade/Class 18-8 Maximum Thickness 5.6 mm Minimum Thickness 5.6 mm Pack Size Small Pack Rockwell Hardness B83 to B95 Spherical Washer Type Spherical Washer Assembly System of Measurement Metric Top Washer Inside Diameter 8.4 mm Top Washer Outside Diameter 17 mm 1 Pair