Coupling Nut Material Grade/Class Grade 2H Material Steel Finish Black Oxide Thread Size 5/8 In.-11 Thread Style Fully Threaded Hex Width 1 1/16 in Overall Length 2 1/8 in Dimensional Standards ASME B18.2.2 Material Quality Standards ASTM A194 2H System of Measurement Inch Thread Direction Right Hand Pack Size Small Pack Rockwell Hardness 28 Min