Allen Nut System of Measurement Inch Insert Diameter 63/64 in Overall Length 1 1/64 in Installed Length Not Applicable Thread Size M18-2.50 Thread Direction Right Hand Thread Type Coarse Flange Diameter Not Applicable Flange Thickness Not Applicable Material Steel Material Grade/Class Grade 2H Finish Black Oxide Body Texture Knurled Compatible Material Metal Drill Bit Size 1 1/64 in Maximum Hole Diameter 1.028 in Minimum Material Thickness 1.01 in