Precision Twist Drill Aircraft Extension Drill, Type J Extra Length Heavy Duty, Series: CO500-12, 1/4 in Drill - Fraction, 0.25 in Drill - Decimal Inch, 12 in Overall Length, 4XD Cutting Depth, 2 Flutes, Spiral Flute, 2-3/4 in Flute Length, 1/4 in Shank, Straight Shank, 135 deg Point, Split/Self-Centering Point, Right Hand Cutting Direction, HSS-E Cutting Edge, HSS-E, Bronze, Applicable Materials: Free Machining Stainless Steel, Austenitic, Ferritic + Austenitic, Martensitic, Precipitation Hardened Steel, Lamellar Graphite, Nodular Graphite/Malleable Cast Iron, Nickel, Alloyed, Alloy Steel/Hardened Steel and Tempered Steel