Lock Washer, Internal/External Tooth, Type A, Carbon Steel, Finish Zinc, Fits Bolt Sizes #6, Inside Dia. 0.150 In., Outside Dia. 0.510 In., Thickness 0.028 In., Rockwell Hardness C40 to C50, Helps Prevent Loosening, For Use With Small Screws, Meets/Exceeds ASME B 18.21. 1, Refills -, Package Quantity 100. This item has been restricted from sale in the following state (s): []