Lock Washer EN 1.7182 Carbon Steel Fits Bolt Sizes 1/2 In. Inside Dia 0.53 In. Outside Dia 0.77 In. Thickness 0.1 In. Thickness Tolerance +/- .01 Color Silver Rockwell Hardness Min 46 HRC High Vibration Dynamic Loads Critical Bolted Joints Extreme Conditions For Use With Bolts Nuts Hex Head Cap Screws Socket Head Cap Screws Adhesives Washers Package Quantity 10