Hertel C.E03.0409 Aircraft Extension Drill Bit No. 20

Product Description

The HERTEL C.E03.0409 is a No. 20 wire-size aircraft extension drill bit engineered for precision drilling in tight or deep-access applications. Built from high-speed steel with an oxide finish, it features a 135-degree split point that is self-centering and reduces walking on entry, eliminating the need for a center punch in most setups. The bit measures 6 inches in overall length with a 2.125-inch spiral flute, giving technicians the extended reach required in aircraft, HVAC panel, and structural fabrication work. The tapered web and web-thinned geometry reduce thrust and improve chip evacuation. Licensed HVAC technicians, aviation mechanics, and sheet-metal fabricators are the primary installers of this tooling.

This bit is suited for general-purpose drilling in metal, sheet stock, and structural materials where standard-length bits cannot reach. The 0.1610-inch decimal diameter corresponds to a No. 20 wire gauge, a common size for pilot holes, rivet holes, and fastener clearance holes in light aircraft structures and mechanical enclosures. Right-hand cutting direction is standard for conventional drill press and hand-drill use. The NAS 907 standard compliance makes it appropriate for aerospace and aviation maintenance environments where tooling specifications are controlled.

Key Features

• 135-degree split point with self-centering geometry reduces bit walk on entry
• Web-thinned, tapered web construction lowers cutting thrust and improves chip clearance
• High-speed steel construction with oxide finish for corrosion resistance and reduced friction
• 6-inch overall length provides extended reach for deep or obstructed drilling locations
• No. 20 wire size (0.1610 inches) for rivet, pilot, and fastener clearance holes
• Compliant with NAS 907 standards for controlled aerospace tooling environments

Compatibility

Designed as a general-purpose aircraft extension drill bit for use with standard straight-shank drill chucks in hand drills, right-angle drills, and drill presses where a No. 20 wire-size bit with extended reach is required.

Installation Notes

This bit is installed by machinists, sheet-metal mechanics, and aviation maintenance technicians using conventional drill equipment with a straight-shank chuck. Secure the workpiece before drilling and verify chuck grip on the straight-cylindrical shank before applying power. Use appropriate cutting fluid for harder metals to extend tool life and maintain hole quality. Follow applicable workplace safety standards and aviation maintenance documentation requirements when drilling aircraft structure.