Large O.D. Oversized Washer, Flat Washer Type Oversized, Dimensional Standards ASME B18.22.1, Material Steel, Material Grade/Class Case Hardened, Finish Zinc-Plated, For Screw Size 5/16 in, Inside Diameter 0.328 in, Outside Diameter 5/8 in, Maximum Thickness 3/64 in, System of Measurement Inch, Minimum Thickness 3/64 in, Color Silver, Inside Diameter Tolerance +/-0.010 in, Material Quality Standards ASTM A108, Outside Diameter Tolerance +/-0.010 in, Pack Size Small Pack, Rockwell Hardness B55