Triumph® Aircraft Extension Drill, Heavy Duty, Series: T6HH, 1/4 in Drill Size - Fraction, 0.25 in Drill Size - Decimal Inch, 6 in Overall Length, 2-3/4 in Flute Length, 135 deg Point, Split Point, HSS, Black Oxide, Applicable Materials: Cast Iron, Low Medium Carbon and High-Tensile Strength Alloys and Steel