Precision Twist Drill 6001281 Letter F Aircraft Extension Drill

Product Description

The PRECISION TWIST DRILL 6001281 is a Letter F aircraft extension drill bit designed for deep-reach drilling in metalworking and aerospace maintenance applications. Built from high speed steel with an oxide finish, it features a 135-degree split point that is self-centering and eliminates the need for a center punch on most surfaces. The straight-cylindrical shank measures 0.257 inches in diameter and the spiral flute length runs 2.875 inches, giving technicians extended reach into confined or recessed bore locations. The web-thinned, tapered web configuration reduces thrust and improves chip evacuation during extended drilling cycles. This is a general-purpose tool suited for professional machinists, aircraft maintenance technicians, and heavy fabrication crews.

This drill bit is built for applications requiring extended reach beyond the capacity of standard-length drill bits. Typical use cases include aircraft structural work, deep-hole drilling in sheet metal assemblies, and production drilling in fabrication shops where workpiece geometry prevents the use of jobber-length drills. The 4xD flute-to-diameter ratio provides adequate chip clearance during through-hole drilling in aluminum, mild steel, and similar materials. The Series 502-6 designation places this bit within a recognized family of aircraft-grade extension drills. It meets NAS 907 Type B standards, making it appropriate for regulated aerospace and defense maintenance environments.

Key Features

• Letter F sizing at 0.257 inches diameter for precise hole sizing without reaming in many applications
• 135-degree split point is self-centering and reduces walking on entry
• High speed steel construction with oxide finish for corrosion resistance and reduced friction
• 2.875-inch spiral flute length with 4xD ratio supports efficient chip removal in deep holes
• Web-thinned tapered web reduces cutting thrust and extends tool life
• Meets NAS 907 Type B standards for aerospace and defense maintenance use

Compatibility

Designed as an OEM-style replacement and standard-fit extension drill for applications requiring a Letter F diameter straight-shank bit conforming to NAS 907 Type B specifications.

Installation Notes

Install and remove drill bits only with the machine powered down and the spindle fully stopped. Secure the straight-cylindrical shank firmly in a keyed or keyless chuck rated for the shank diameter before applying any load. Use appropriate cutting fluid for the workpiece material to extend tool life and maintain hole quality. Follow applicable shop safety standards and any relevant aerospace maintenance manual procedures when drilling structural components.