Jam Nut, Hex Type Heavy Jam, Finish Zinc Plated, Material Steel, Material Grade/Class Grade A, Thread Size 5/16 In.-18, Hex Width 9/16 in, Hex Height 13/64 in, Dimensional Standards ASME B18.2.2, System of Measurement Inch, Thread Direction Right Hand, Pack Size Small Pack, Thread Type Coarse, Package Quantity 100