Castle Nut, Finish Zinc Plated, Material Steel, Material Grade/Class Grade 2, Thread Size 1 1/2 In.-12, Hex Width 2 1/4 in, Hex Height 1 9/32 in, Hex Type Standard Hex, Lock Type Slotted Castle, Material Quality Standards ASTM 563, System of Measurement Inch, Thread Direction Right Hand, For Pin Diameter 5/16 in, Maximum Slot Width 0.46 in, Pack Size Small Pack, Package Quantity 5