Allen Nut System of Measurement Inch Insert Diameter 51/64 in Overall Length 27/32 in Installed Length Not Applicable Thread Size 1/2 In.-20 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 53/64 in Maximum Hole Diameter 0.831 in Minimum Material Thickness 0.836 in