Lock Washer Internal Tooth Type A Carbon Steel Finish Zinc Fits Bolt Sizes #6 Inside Dia 0.150 In. Outside Dia 0.295 In. Thickness 0.022 In. Rockwell Hardness C40 to C50 Helps Prevent Loosening For Use With Small Screws Meets/Exceeds ASME B18.21.1 Refills - Package Quantity 100