USS Washer USS Through Hardened Steel Finish Zinc Yellow Fits Bolt Sizes 1-1/4 In. Inside Dia 1-3/8 In. Outside Dia 3 In. Thickness 0.136 to 0.192 In. Rockwell Hardness RC38 to 45 Load Distributing For Use With Grade 8 Fastener Meets/Exceeds ASME/ANSI B 18.22 ASTM F436 Package Quantity 5