Precision Twist Drill 6001238 Aircraft Extension Drill

Product Description

The PRECISION TWIST DRILL 6001238 is a wire-gauge aircraft extension drill bit engineered for demanding drilling applications in aerospace, automotive, and general metalworking environments. Built from high speed steel with an oxide finish, this bit features a 135-degree split point that is self-centering, reducing walking and the need for a center punch on most metal surfaces. The straight-cylindrical shank measures 0.177 inches in diameter and mates reliably with standard chucks. At 12 inches in overall length with a 2.1875-inch spiral flute, this extension drill reaches deep or recessed bore locations that standard-length bits cannot access. Installed by machinists, maintenance technicians, and aircraft sheet-metal mechanics working within NAS 907 Type B standards.

This drill bit is suited for production and repair work where reach is critical — blind holes, structural framing, deep cavities, and aerospace skin drilling are common applications. The extended length makes it particularly useful when working through fixtures, guides, or layered assemblies where a standard jobber-length bit falls short. The 2-flute spiral design with tapered web and web-thinned geometry promotes efficient chip evacuation in both ferrous and non-ferrous materials. Right-hand cutting direction is standard for conventional drilling setups.

Key Features

• 135-degree split point for self-centering entry without a center punch on most metals
• Wire size 16 (0.177 inches) straight-cylindrical shank for secure chuck engagement
• 12-inch overall length provides extended reach into deep or restricted bore locations
• High speed steel construction with oxide finish for wear resistance in general-purpose metal drilling
• 2-flute spiral geometry with tapered, web-thinned web for efficient chip removal
• Meets NAS 907 Type B standards — suitable for aerospace and precision metalworking applications

Compatibility

Designed as an OEM-style replacement and production drill bit for use with standard straight-shank drill chucks in aircraft extension drilling applications conforming to NAS 907 Type B specifications.

Installation Notes

Installation and use of this drill bit should be performed by qualified machinists or aircraft sheet-metal mechanics familiar with proper speeds and feeds for high speed steel tooling in the applicable work material. Secure the shank fully in the chuck and verify runout before drilling. Avoid excessive feed pressure, which can cause bit deflection at extended length or premature cutting-edge failure. Follow applicable workplace safety and aviation maintenance standards when drilling structural components.