Precision Twist Drill 6001232 Aircraft Extension Drill Bit

Product Description

The PRECISION TWIST DRILL 6001232 is a high speed steel aircraft extension drill bit designed for deep-reach drilling applications where standard-length bits cannot access the work area. Built to Series 501-12 specifications, this bit features a 135-degree split point that is self-centering and web-thinned, eliminating the need for a center punch and reducing walking on entry. The 0.189-inch diameter straight-cylindrical shank and spiral flute geometry are ground to NAS 907 Type B standards. An oxide finish provides baseline lubricity and corrosion resistance. With a 12-inch overall length and a 2.3125-inch flute length, this bit is suited for reaching through structural members, deep cavities, or stacked materials common in aerospace, HVAC ductwork, and sheet metal fabrication.

This aircraft extension drill bit is used in applications that require extended reach beyond what a jobber-length bit provides. Typical installations include drilling through aircraft fuselage panels, HVAC equipment frames, electrical enclosures, and structural steel where the drill motor must be kept well clear of the work surface. Right-hand cutting direction and a 4xD flute-length-to-diameter ratio make this bit appropriate for general-purpose through-hole drilling in metal. It is sold individually and intended for use by machinists, sheet metal workers, HVAC technicians, and aircraft maintenance professionals.

Key Features

• 135-degree split point with web thinning for self-centering entry and reduced thrust
• 12-inch overall length delivers extended reach in deep or restricted-access drilling situations
• High speed steel construction handles general-purpose metal drilling across a range of hardnesses
• Oxide finish provides corrosion resistance and mild lubricity during use
• Straight-cylindrical shank at 0.189 inches fits standard drill chucks without reduction sleeves
• Built to NAS 907 Type B standards for dimensional and performance consistency

Compatibility

Designed as a general-purpose aircraft extension drill bit conforming to NAS 907 Type B standards, compatible with any drill chuck accepting a 0.189-inch straight-cylindrical shank.

Installation Notes

Installation is performed by machinists, sheet metal workers, and aviation maintenance technicians using corded or pneumatic drill motors with a chuck rated for the shank diameter. Secure the workpiece before drilling to prevent rotation and material movement. Apply cutting fluid appropriate for the base material to extend tool life and improve hole finish. Inspect the split point and flute edges for wear or chipping before each use, as a damaged point on an extension bit can deflect inside deep bores.