Allen Nut System of Measurement Inch Insert Diameter 5/16 in Overall Length 5/16 in Installed Length Not Applicable Thread Size #10-32 Thread Direction Right Hand Thread Type Fine Flange Diameter Not Applicable Flange Thickness Not Applicable Material Stainless Steel Material Grade/Class 18-8 Finish Plain Body Texture Knurled Compatible Material Metal Drill Bit Size 21/64 in Maximum Hole Diameter 0.327 in Minimum Material Thickness 0.319 in