Precision Twist Drill 6001209 Aircraft Extension Drill Bit

Product Description

The PRECISION TWIST DRILL 6001209 is a high speed steel aircraft extension drill bit designed for deep-reach drilling applications where a standard-length bit cannot access the work area. Built to Series 500-6 specifications, it features a 135-degree split point that self-centers on contact, eliminating the need for a center punch on most materials. The two-flute spiral design with web thinning reduces cutting resistance and improves chip evacuation. An oxide finish provides baseline lubricity and corrosion resistance. This bit is sized at 5/16 inch (0.3125 inch decimal) with a 3-3/16 inch flute length, making it well suited for extended reach in structural, sheet metal, and aircraft-style drilling work.

This extension drill bit is used in applications where access depth exceeds the reach of a jobber-length bit, such as drilling through structural members, deep flanges, or confined assemblies in aerospace, HVAC fabrication, and sheet metal work. The straight-cylindrical shank fits standard drill chucks without adapters. Right-hand cutting direction is compatible with conventional drill press and handheld drill operation. General-purpose tool performance rating makes it appropriate for a range of ferrous and non-ferrous materials at typical shop feeds and speeds.

Key Features

• 135-degree split point self-centers without a center punch, reducing setup time
• Web-thinned tapered web reduces thrust and extends tool life in production use
• Extended flute length of 3-3/16 inches enables drilling in deep or hard-to-reach locations
• High speed steel construction handles a broad range of metals at conventional cutting speeds
• Oxide finish provides light lubricity and surface protection
• Meets NAS 907 Type B standard for aircraft-quality drill bit geometry

Compatibility

Designed as a general-purpose aircraft extension drill bit with a straight-cylindrical shank compatible with standard three-jaw drill chucks. Sized to NAS 907 Type B requirements for use in aerospace and structural drilling applications.

Installation Notes

This bit is installed and removed by a qualified machinist, aircraft mechanic, or sheet metal tradesperson using a standard keyed or keyless drill chuck. Ensure the drill is fully powered down and the chuck is secured before beginning work. Do not exceed the recommended feed rate for the workpiece material, as excessive pressure on an extended bit can cause deflection or breakage. Inspect the split point and cutting edges before each use and replace the bit if chipping or wear is observed.