Spherical Flange Nut Material Grade/Class 18-8 Material Stainless Steel Finish Black Oxide Thread Size 1/4 In.-20 Hex Width 1/2 in Hex Height 7/32 in Flange Diameter 1 5/8 in System of Measurement Inch Compatible Washer Manufacturer Part Number 47741 Maximum Rotation 5 Degrees Nut Finish Plain Pack Size Small Pack Rockwell Hardness 27 Rockwell