Precision Twist Drill 6001303 Letter K Aircraft Extension Drill

Product Description

The PRECISION TWIST DRILL 6001303 is a Letter K (0.281 inch diameter) aircraft extension drill bit designed for deep-reach drilling applications in metal and aerospace-grade materials. Built from high speed steel with an oxide finish, it features a 135-degree split point for self-centering starts without a center punch. The two-flute spiral design with a tapered web and web-thinned construction reduces cutting resistance and improves chip evacuation. With a 2.9375-inch flute length and a 6-inch overall length, it gives technicians the extended reach needed in confined or deep-cavity work. Right-hand cutting direction is standard. Series 502-6.

This drill bit is suited for aircraft maintenance, sheet metal fabrication, and general-purpose metalworking where standard-length bits cannot reach. The 4xD flute-length-to-diameter ratio makes it effective on aluminum, mild steel, and similar structural metals. It is commonly used by aviation maintenance technicians, machine shop operators, and industrial maintenance crews working on structural assemblies where access is limited. The straight-cylindrical shank seats securely in standard drill chucks and extension holders without modification.

Key Features

• Letter K size — 0.281 inch diameter for precise hole sizing
• 135-degree split point with self-centering tip eliminates need for a center punch
• 6-inch overall length provides extended reach into deep or restricted work areas
• High speed steel construction with oxide finish for wear and corrosion resistance
• Web-thinned tapered web reduces thrust and improves chip flow
• Meets NAS 907 Type B standard for aircraft-grade drilling applications

Compatibility

Designed as an OEM-style replacement drill bit compatible with standard drill chucks and extension holders accepting a 0.281 inch straight-cylindrical shank, conforming to NAS 907 Type B specifications.

Installation Notes

Installation and use should be performed by qualified machinists, aircraft maintenance technicians, or industrial tradespeople familiar with metal drilling procedures. Secure the workpiece firmly before drilling and use appropriate cutting fluid to extend tool life on ferrous materials. Inspect the drill point for wear or chipping before each use and replace if the split point shows damage. Operate at manufacturer-recommended speeds for the material being drilled to avoid overheating the high speed steel cutting edge.