Drill America - GLBCOX121/4 1/4" x 12" Cobalt Aircraft Extension 1/4 in Product Details Is Discontinued By Manufacturer : No Product Dimensions : 6 x 4 x 2 inches; 1.6 ounces Item model number : GLBCOX121/4 Manufacturer : Drill America Country of Origin : China Material: Cobalt Cutting Diameter: 0.25 Inches Finish Type: Gold Shank Type: Round Cutting Angle String: 135 Degrees Effective in drilling tough, high tensile strength materials like stainless steel, inconel and titanium 135 split point tip prevents drill from walking Round shanks allow use with a wide variety of tool holding systems Gold oxide is a thinner oxide surface treatment than black oxide typically used to identify cobalt steel tools; performance is similar to uncoated tools 12" overall length for drilling where extra length for reach is required Drill America Cobalt Aircraft Extension Drills are similar to high-speed steel, but with more cobalt for improved performance when cutting harder metals such as stainless steel or nickel alloys. Gold oxide is a thinner oxide surface treatment than black oxide typically used to identify cobalt steel tools; performance is similar to uncoated tools. Drill America Aircraft Extension Drills are manufactured to National Aerospace Standard 907. The 135 split point is self-centering and reduces thrust. Sizes smaller than 1/16 in. have the 118 standard point. Drill America Aircraft Extension Drills are available in 6 in. and 12 in. overall lengths when extra reach is required.