Hertel C.E05.0305 Aircraft Extension Drill Bit No. 31

Product Description

The HERTEL C.E05.0305 is an aircraft extension drill bit designed for reach-intensive drilling applications where standard-length bits cannot access the workpoint. Built from high-speed steel with an oxide finish, this bit measures 12 inches in overall length and carries a No. 31 wire gauge size, equal to 0.1200 inches in decimal. The 135-degree split point geometry is self-centering and reduces walking on entry, which is especially useful when drilling into curved or angled metal surfaces. Web thinning improves chip clearance and reduces thrust force at the cutting edge. This bit is suited for general-purpose metal drilling in aerospace, structural, and fabrication environments.

Aircraft extension drill bits like the C.E05.0305 are commonly used by aircraft maintenance technicians, structural fabricators, and sheet metal workers who need to reach fastener holes in confined airframe bays, ribs, or flanges. The 12-inch extension allows access to areas that standard jobber-length bits cannot reach. Right-hand spiral fluting with a 1.625-inch flute length handles chip evacuation in these deeper or angled setups. The straight cylindrical shank fits standard drill chucks without adapters. This bit is a general-purpose tool appropriate for ferrous and non-ferrous metals encountered in aerospace and industrial fabrication work.

Key Features

• No. 31 wire gauge size, 0.1200 inches decimal diameter
• 12-inch overall length for extended reach in confined spaces
• 135-degree split point is self-centering and reduces drill walk on entry
• High-speed steel construction with oxide finish for general-purpose metal drilling
• Web-thinned tapered web reduces cutting thrust and improves chip flow
• Right-hand spiral flute with 1.625-inch flute length, two flutes
• Meets NAS 907 standard

Compatibility

Designed as an OEM-style replacement or direct-use aircraft extension drill bit for applications requiring a No. 31 wire gauge straight-shank bit in standard drill chucks used in aerospace maintenance and metal fabrication.

Installation Notes

This bit is installed and operated by aircraft maintenance technicians, structural fabricators, and machinists using handheld or stationary drill equipment. Secure the straight cylindrical shank firmly in the drill chuck before use and verify chuck runout is within acceptable limits for the application. Wear appropriate eye and hand protection when drilling. Follow applicable workplace safety standards and any relevant aerospace maintenance manual procedures when working on aircraft structures.