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 1 3/4 in Inside Diameter 1.875 in Outside Diameter 4 in Maximum Thickness 0.213 in System of Measurement Inch Minimum Thickness 0.153 in Pack Size Small Pack Resistance Properties Corrosion Resistant Rockwell Hardness 38HRC Thickness Tolerance +/-0.030 in Package Quantity 10