Hex Locknut Serrated Flange Low Carbon Steel Finish Zinc Plated Grade 2 Property Class 2 Thread Size 6-32 6-32 Thread Type UNC Thread Direction Right Hand Width 5/16 In. Height 11/64 In. Rockwell Hardness HR15N 78 to 90 Application Requires a greater amount of torque to loosen than to tighten the nut. Will span oversized or poorly aligned holes. Flange provides a more uniform bearing-stress to clamp-force ratio than other low carbon lock nuts. Does not gall screw threads.