Coupling Nut Material Grade/Class Grade 5 Material Steel Finish Black Oxide Thread Size 1/4 In.-20 Thread Style Fully Threaded Hex Width 1/2 in Overall Length 5/8 in Dimensional Standards RoHS Compliant with Excemption 6 Material Quality Standards Grade 2 System of Measurement Inch Thread Direction Right Hand Color Black Pack Size Small Pack Rockwell Hardness 85-90 Rockwell on 15N Scale