Flat Washer Flat Washer Type Standard Dimensional Standards ASME B18.22.1 Material Stainless Steel Material Grade/Class 316 Finish NL-19 For Screw Size 1/2 in Inside Diameter 0.563 in Outside Diameter 1 3/4 in Maximum Thickness 0.192 in System of Measurement Inch Minimum Thickness 0.136 in Color Silver Pack Size Small Pack Resistance Properties Corrosion Resistant Rockwell Hardness B80 Thickness Tolerance +0.086 to 0.132 in Package Quantity 50