Castle Nut Finish Black Oxide Material Steel Material Grade/Class Grade 5 Thread Size 5/8 In.-18 Hex Width 15/16 in Hex Height 33/64 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 5/32 in Maximum Slot Width 0.24 in Minimum Slot Width 0.18 in Overall Height 47/64 in Pack Size Small Pack Package Quantity 25