Item:Threaded Shank Drill Bit; Material - Machining:Cobalt; Shank Thread Size:1/4"-28; Finish - Machining:Black Oxide; Measurement System:Wire; Drill Bit Size:#21; Drill Bit Point Angle:135 Degrees; Decimal Equivalent:0.1590; Drill Bit Point Type:Split Point; Flute Type:Spiral; Flute Length:9/16 In; Cutting Direction:Right Hand; Overall Length:1 1/2 In; Drill Bit Grouping:Individual; Shank Type - Machining:Threaded; Aircraft Drill:No; Standards:Not Rated; Material Grade - Machining:M35;