Hertel C.E05.0258 Aircraft Extension Drill Bit No. 38

Product Description

The HERTEL C.E05.0258 is a No. 38 aircraft extension drill bit engineered for deep-reach drilling in tight or recessed locations. Built from high-speed steel with an oxide finish, it runs a 135-degree split point that self-centers on contact, reducing walking on curved or coated surfaces. The bit measures 12 inches in overall length with a 1.4375-inch spiral flute, making it well suited for applications where a standard-length bit cannot reach. Web thinning reduces thrust requirements and helps maintain clean, consistent holes. Licensed technicians and aerospace maintenance pros are the primary users of this tool.

This extension drill bit is intended for general-purpose drilling in aerospace, aviation maintenance, and industrial fabrication environments. The extended reach allows work in aircraft fuselage panels, deep frames, and structural members where access is restricted. The right-hand spiral flute and straight cylindrical shank are compatible with standard drill chucks and pneumatic drill motors commonly used on flight line and in sheet metal shops. It conforms to NAS 907 standards, which govern aircraft extension drill geometry and tolerances.

Key Features

• 135-degree split point for self-centering entry without a center punch
• 12-inch overall length for deep-reach and restricted-access drilling
• High-speed steel construction with oxide finish for wear resistance
• Web-thinned tapered web reduces drilling thrust and heat buildup
• Right-hand cutting, 2-flute spiral design for efficient chip evacuation
• Conforms to NAS 907 aircraft extension drill standards

Compatibility

Designed as a general-purpose aircraft extension drill bit fitting standard straight cylindrical chuck systems used in aerospace and industrial drilling applications.

Installation Notes

Aircraft extension drill bits are typically installed and operated by aviation maintenance technicians, sheet metal mechanics, and industrial machinists. Secure the straight shank fully in the drill chuck before operation and verify runout before drilling into finished panels. Use appropriate cutting fluid or lubricant when drilling hard alloys to extend tool life. Follow applicable workplace safety and aviation maintenance manual procedures for the specific airframe or structure being worked.