Chicago-Latrobe - Screw Machine Drill, Heavy Duty, Series: 159-TN/2159, Imperial, D Drill - Letter, 0.246 in - Decimal Inch, 2-1/2 in Overall Length, 1-3/8 in Depth of Cut, 2 Flutes, Right Hand Spiral Flute, 1-3/8 in Flute Length, 0.246 in Dia. x 1.1 in. Bore x 1.1 in. L of 25 in. Shank, Straight Shank, 135 Degree Point, Parting Point, Right Hand Cutting Direction, HSS Cutting Edge, TiN Coated, Applicable Materials: Alloy Steel, Carbon Steel, Cast Iron and Tool Steel