USS Washer Flat Washer Type USS Dimensional Standards ASME B18.22.1 Material Steel Material Grade/Class Grade 2 Finish Black Oxide For Screw Size 1 3/8 in Inside Diameter 1.5 in Outside Diameter 3 1/4 in Maximum Thickness 0.18 in System of Measurement Inch Minimum Thickness 0.18 in Pack Size Small Pack RoHS Compliant No Thickness Tolerance +0.033/-0.027 in Package Quantity 15