Flat Washer, Flat Washer Type Standard, Dimensional Standards ASME B18.22.1, Material Stainless Steel, Material Grade/Class 18-8, Finish NL-19, For Screw Size 5/16 in, Inside Diameter 0.375 in, Outside Diameter 7/8 in, Maximum Thickness 5/64 in, System of Measurement Inch, Minimum Thickness 3/64 in, Color Silver, Material Quality Standards Not Applicable, Pack Size Small Pack, Resistance Properties Corrosion-Resistant, Rockwell Hardness B70, Thickness Tolerance +0.064 to 0.104 in