Hex Nut, Hex Type Standard Hex, Finish Black Oxide, Material Grade/Class Grade 5, Material Steel, Thread Size 9/16 In.-18, Hex Width 7/8 in, Hex Height 31/64 in, Manufacturer Location Made in USA*, Dimensional Standards ASME B18.2.2, System of Measurement Inch, Thread Direction Right Hand, Pack Size Small Pack, Rockwell Hardness C19 to C30, Thread Type UNF, Package Quantity 25