Latrobe Chicago Screw Machine Drill, Heavy Duty, Series: 159, Imperial, E Drill - Letter, 0.25 in. Drill - Decimal Inch, 2-1/2 in. Overall Length, 3XD Depth of Cut, 2 Flutes, Right Hand Spiral Flute, 1-3/8 in. Flute Length, Straight Shank, 1/4 in. Diameter x 1-1/8 in. 35 DEG Point, Split Point, Right Hand Cutting Direction, HSS Cutting Edge, Black Vapor Oxide, Applicable Materials: Alloy Steel, Carbon Steel, Cast Iron and Tool Steel