USS Washer Flat Washer Type USS Dimensional Standards ASME B18.22.1 Type A Wide USS Standard Material Steel Material Grade/Class Grade 2 Finish Black Oxide For Screw Size 3/16 in Inside Diameter 0.25 in Outside Diameter 9/16 in Maximum Thickness 0.047 in System of Measurement Inch Minimum Thickness 0.047 in Pack Size Small Pack Resistance Properties Corrosion Resistant Rockwell Hardness 38HRC Thickness Tolerance +/-0.014 in Package Quantity 100