Precision Twist Drill 6001321 Letter E Aircraft Drill Bit

Product Description

The PRECISION TWIST DRILL 6001321 is a Letter E (0.2500 inch) high speed steel aircraft extension drill bit designed for deep-hole drilling applications where standard-length bits cannot reach. Built to Series 500-12 specifications, this bit features a 135-degree split point that is self-centering and eliminates the need for a center punch on most surfaces. The web-thinned, tapered web configuration reduces thrust and improves chip clearance. An oxide finish provides basic lubricity and corrosion resistance during service. Licensed HVAC technicians, sheet metal workers, aircraft maintenance technicians, and general metalworking trades use this bit for precision through-hole drilling in tight or extended-reach areas.

This drill bit is suited for drilling steel, aluminum, and other metals in residential, commercial, and industrial settings where standard-length bits are inadequate. The 12-inch overall length and 2.75-inch spiral flute length make it well suited for drilling through structural members, electrical panels, HVAC casings, and similar applications requiring extended reach. It is a general-purpose tool appropriate for any trade requiring accurate, clean holes in metallic substrates.

Key Features

• Letter E size — 0.2500 inch (1/4 inch) diameter for exact fractional sizing
• 135-degree split point is self-centering and reduces walking on entry
• 12-inch overall length provides extended reach in confined or deep-hole applications
• High speed steel construction handles general-purpose metal drilling without coolant on most materials
• Web-thinned tapered web reduces drilling thrust and improves chip evacuation
• Oxide finish adds surface lubricity and mild corrosion resistance
• Right-hand cutting direction, two flutes, straight-cylindrical shank for standard chuck compatibility

Compatibility

Designed as a general-purpose aircraft extension drill bit compatible with any standard drill chuck accepting a 1/4 inch straight-cylindrical shank. Meets NAS 907 Type B standards.

Installation Notes

This bit is installed and operated by any trade performing metalwork, including HVAC installers, electricians, and sheet metal workers. Secure the straight-cylindrical shank firmly in a keyed or keyless chuck before use. Always wear appropriate eye protection and secure the workpiece to prevent rotation. For extended-length bits, use reduced feed pressure to minimize bit deflection and prevent breakage.