Jam Nut, Hex Type Jam Hex, Finish Black Oxide, Material Steel, Material Grade/Class Grade A, Thread Size 5/8 In.-18, Hex Width 15/16 in, Hex Height 25/64 in, Dimensional Standards ASME B18.2.2, System of Measurement Inch, Thread Direction Right Hand, Pack Size Small Pack, Thread Type Fine, Package Quantity 10