Coupling Nut Material Grade/Class Grade 2H Material Steel Finish Black Oxide Thread Size 1/4 In.-20 Thread Style Fully Threaded Hex Width 1/2 in Overall Length 7/8 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