Spherical Washer Bottom Washer Inside Diameter 19 mm Bottom Washer Outside Diameter 30 mm Bottom Washer Radius 22 mm Finish Plain For Screw Size M16 Material Stainless Steel Material Grade/Class 18-8 Maximum Thickness 9.6 mm Minimum Thickness 9.6 mm Pack Size Small Pack Rockwell Hardness B83 to B95 Spherical Washer Type Spherical Washer Assembly System of Measurement Metric Top Washer Inside Diameter 17 mm Top Washer Outside Diameter 30 mm 1 Pair