Hertel C.E05.0737 Aircraft Drill Bit Letter L 135pt Hss

Product Description

The HERTEL C.E05.0737 is an aircraft extension drill bit sized to Letter L (0.2900 inches decimal) with a 12-inch overall length, designed for deep-reach drilling applications where a standard-length bit cannot access the worksite. 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 spiral flute geometry and web-thinned, tapered web construction reduce thrust and improve chip evacuation. This bit is installed by machinists, aviation maintenance technicians, and fabricators working on structural assemblies, airframes, and deep-cavity metalwork.

Aircraft extension drill bits like the C.E05.0737 are used when drilling through deep structural members, stacked assemblies, or confined spaces where bit reach is critical. The 12-inch overall length and 2.9375-inch flute length make it suitable for through-drilling in aircraft panels, sheet metal stacks, and heavy fabrication work. The right-hand cutting direction and straight cylindrical shank are compatible with standard drill chucks and handheld pneumatic drill motors common in aviation and industrial maintenance environments. This bit conforms to NAS 907 standards.

Key Features

• Letter L size (0.2900 inches) with 12-inch overall length for extended-reach drilling
• 135-degree split point with self-centering geometry eliminates center-punch step
• High-speed steel construction with oxide finish for general-purpose metal drilling
• Web-thinned tapered web reduces cutting resistance and thrust load
• Spiral flute with right-hand cutting direction for efficient chip removal
• Conforms to NAS 907 standard for aircraft drill bit dimensional requirements

Compatibility

Designed for use with standard straight-cylindrical shank drill chucks in handheld and bench-mounted drilling equipment used in aviation maintenance, sheet metal fabrication, and general industrial metalworking applications.

Installation Notes

Aircraft extension drill bits should be installed by qualified aviation maintenance technicians or machinists familiar with applicable shop practices and safety standards. Secure the straight cylindrical shank firmly in the chuck before operation and verify runout is within acceptable limits. Use appropriate cutting fluid for the workpiece material to extend bit life and improve hole quality. Inspect the cutting edges and web before each use and replace the bit if chipping or excessive wear is observed.