Lock Nut, Finish Zinc-Plated, Material Steel, Material Grade/Class Grade A, Thread Size 5/16 In. -18, Hex Width 1/2 in, Hex Height 11/64 in, Lock Type Top Lock Distorted Thread, Dimensional Standards ASME 18.18, ASME B 1.1, ASME B 18.16. 4, SAE J429, Material Quality Standards ASTM F788, System of Measurement Inch, Hex Type Flange Hex, Thread Direction Right Hand, Color Clear, Industry Standards ASME B 18.16. 4, Insert Material Not Applicable, Pack Size Bulk Pack. This item has been restricted from sale in the following state (s): []