Hertel C.E03.0803 Aircraft Extension Drill Bit Letter O

Product Description

The HERTEL C.E03.0803 is an aircraft extension drill bit designed for deep-reach drilling applications where a standard-length bit cannot access the workpoint. Sized at Letter O (0.3160 inches decimal), it features a 135-degree split point that self-centers on contact and reduces the need for a center punch. The high-speed steel construction with an oxide finish provides heat resistance during high-speed cutting operations. At 6 inches overall length with a 3.1875-inch spiral flute, this bit delivers the extended reach required in aerospace, structural, and tight-access fabrication work. Installation and use require a straight, cylindrical shank chuck.

This bit is suited for drilling through aluminum, mild steel, and similar materials encountered in aircraft assembly, structural fabrication, and maintenance operations. The 2-flute spiral design promotes chip evacuation in deep-hole applications. Web thinning with a tapered web configuration reduces cutting resistance at the tip, making it appropriate for production drilling and field repair scenarios where clean entry holes and consistent sizing are required. It is typically used by aerospace technicians, structural metalworkers, and machining professionals working to NAS 907 standards.

Key Features

• Letter O size: 0.3160 inches decimal diameter for precise fit to spec
• 135-degree split point with self-centering geometry eliminates center-punch step
• 6-inch overall length provides extended reach into deep or confined workspaces
• High-speed steel construction with oxide finish for heat and wear resistance
• Web-thinned, tapered web configuration reduces thrust and cutting resistance
• Right-hand cutting, 2-flute spiral design promotes efficient chip clearance
• Meets NAS 907 standard for aircraft extension drill bits

Compatibility

Designed as an OEM-style replacement or standard-fit aircraft extension drill bit for use in straight-cylindrical shank chucks requiring a Letter O diameter bit conforming to NAS 907.

Installation Notes

This bit is installed and used by machinists, aerospace technicians, and metalworkers operating drill presses, hand drills, or pneumatic drill motors with compatible straight-shank chucks. Secure the shank fully in the chuck before operation and verify runout before drilling critical-tolerance holes. Use appropriate cutting fluid for the workpiece material to extend tool life and maintain hole quality. Inspect the cutting edges and split point for wear or chipping before each use, particularly in production environments.