Precision Twist Drill 6001236 Aircraft Extension Drill Bit

Product Description

The PRECISION TWIST DRILL 6001236 is a 9/64 inch (0.1406 inch decimal) high speed steel aircraft extension drill bit designed for deep-reach drilling applications in metal, composite, and structural materials. Built to NAS 907 Type B standards, it features a 135-degree split point that self-centers on contact, reducing the need for a center punch and minimizing walking on curved or sloped surfaces. The oxide finish provides corrosion resistance and mild lubricity during cutting. With a 1.75-inch spiral flute length and a total overall length of 12 inches, this bit reaches into recessed cavities and structural members that standard-length bits cannot access. It is a general-purpose tool suited for aviation maintenance technicians, sheet metal workers, structural mechanics, and fabricators who work in confined or deep-bore conditions.

This aircraft extension drill bit is built for applications where reach is critical — drilling through airframe structures, deep structural assemblies, automotive chassis members, and fabricated metal enclosures. The 12-inch overall length combined with the 9/64 inch straight-cylindrical shank allows it to reach blind locations inaccessible to jobber-length bits. The 4xD flute-length-to-diameter ratio supports chip evacuation in deeper passes. It is sold individually and suited for both production and field repair environments.

Key Features

• 135-degree split point with self-centering geometry reduces walking and eliminates center-punch requirements on most metal surfaces
• 12-inch overall length provides extended reach into deep structural cavities and recessed assemblies
• High speed steel construction handles general-purpose metal drilling across a wide range of materials
• Web-thinned tapered web configuration reduces thrust force and improves chip flow
• Oxide finish adds corrosion resistance and reduces friction at the cutting edge
• NAS 907 Type B compliant for use in aerospace and structural applications

Compatibility

Designed as an OEM-style fit for standard straight-cylindrical shank drill chucks accepting a 9/64 inch shank diameter. Belongs to the Series 500-12 aircraft extension drill family from PRECISION TWIST DRILL.

Installation Notes

This bit is installed by licensed aviation maintenance technicians, sheet metal mechanics, and structural fabricators working under applicable maintenance manuals or shop standards. Secure the straight-cylindrical shank firmly in a keyed or keyless chuck before use and verify chuck concentricity to avoid runout on small-diameter bits. When drilling metals, use appropriate cutting fluid to extend tool life and improve hole finish. Inspect the split point for wear or chipping before each use, as a damaged point on a small-diameter extension bit can cause breakage under lateral load.