Castle Nut, Finish Black Oxide, Material Steel, Material Grade/Class Grade 5, Thread Size 1 3/8 In.-6, Hex Width 2 1/16 in, Hex Height 1 13/64 in, Hex Type Standard Hex, Lock Type Slotted Castle, Dimensional Standards ASME B18.2.2, Material Quality Standards ASME B18.2.2, SAE J995, System of Measurement Inch, Thread Direction Right Hand, For Pin Diameter 1/4 in, Maximum Slot Width 0.4 in, Minimum Slot Width 0.31 in, Overall Height 1 13/64 in, Pack Size Small Pack, Package Quantity 5