Flat Washer, Flat Washer Type Standard, Dimensional Standards AMPG 2001 FL.04, Material Steel, Material Grade/Class Case Hardened, Finish Black Oxide, For Screw Size M14, Inside Diameter 15 mm, Outside Diameter 25 mm, Maximum Thickness 3 mm, System of Measurement Metric, Minimum Thickness 3 mm, Color Black, Inside Diameter Tolerance +/-0.010 in, Material Quality Standards ASTM A108, Outside Diameter Tolerance +/-0.010 in, Pack Size Small Pack, Rockwell Hardness C4