Flat Washer Flat Washer Type Standard Dimensional Standards UL Standard Material Stainless Steel Material Grade/Class 316 Finish Plain For Screw Size 1/4 in Inside Diameter 0.25 in Outside Diameter 5/8 in Maximum Thickness 0.045 in System of Measurement Inch Minimum Thickness 0.045 in Color Silver Material Quality Standards ASTM Pack Size Small Pack Resistance Properties Corrosion Resistant