Square Washer, Dimensional Standards AMPG 2017 SQ.01, Material Stainless Steel, Material Grade/Class 18-8, Finish Plain, For Screw Size 1/4 in, Inside Diameter 0.312 in, Outside Diameter Not Applicable, Maximum Thickness 17/64 in, System of Measurement Inch, Minimum Thickness 15/64 in, Material Quality Standards ASTM A582, Pack Size Small Pack, Rockwell Hardness B83, Tensile Strength 90,000 psi, Thickness Tolerance +/-0.030 in