Precision Twist Drill 6001366 Aircraft Extension Drill Bit

Product Description

The PRECISION TWIST DRILL 6001366 is a high speed steel aircraft extension drill bit designed for deep-reach drilling applications where standard-length bits cannot access the workpiece. The 27/64 inch (0.4219 inch decimal) diameter bit features a 135-degree split point for self-centering entry without a center punch, and a web-thinned, tapered web configuration that reduces thrust and improves chip evacuation. The 3-15/16 inch (3.9375 inch decimal) spiral flute length and extended 12-inch overall length make it well suited for structural, aerospace, and sheet metal work. An oxide finish provides corrosion resistance and reduced friction during cutting. This bit is installed and used by machinists, aircraft maintenance technicians, and sheet metal fabricators.

This drill bit is built for general-purpose right-hand cutting in materials commonly encountered in aircraft and structural fabrication environments. The extended overall length of 12 inches gives technicians access to recessed holes and deep assemblies that standard jobber-length bits cannot reach. The straight-cylindrical shank seats securely in standard drill chucks without requiring a special holder. The Series 500-12 designation identifies this as part of PRECISION TWIST DRILL's extended-length aircraft drill line. It is suited for use in both hand-held and drill-press setups where reach and precision entry are required.

Key Features

• 27/64 inch diameter with 0.4219 inch decimal equivalent for precise sizing
• 135-degree split point for self-centering entry without a center punch
• 12-inch overall length for deep-reach and extended-access drilling
• High speed steel construction for durability across general-purpose applications
• Web-thinned tapered web reduces drilling thrust and improves chip flow
• Oxide finish for corrosion resistance and reduced friction
• Meets NAS 907 Type B standards

Compatibility

Designed as an OEM-style replacement and general-purpose aircraft extension drill bit compatible with any standard drill chuck accepting a straight-cylindrical shank of 27/64 inch diameter.

Installation Notes

This bit is installed by machinists, aircraft maintenance technicians, and sheet metal fabricators using standard drill presses or hand-held drill motors. Secure the straight-cylindrical shank fully in the chuck before operation to prevent slippage. Use appropriate cutting fluid for the workpiece material to extend bit life and improve hole finish. Always wear appropriate eye protection and secure the workpiece before drilling.