Chicago-latrobe 11173 Aircraft Extension Drill Bit No. 49

Product Description

The CHICAGO-LATROBE 11173 is a Series 912 aircraft extension drill bit designed for precision drilling in tight or deep-access applications. Built from high-speed steel with an oxide finish, this bit is sized to wire gauge No. 49 (0.0730 inches decimal equivalent) and features a 135-degree split point for self-centering entry without a center punch. The 12-inch overall length gives technicians the reach needed for airframe and structural drilling where standard-length bits fall short. With a 1-inch spiral flute and right-hand cutting direction, it is suited for use in hand-held and drill-press setups across metal fabrication and aerospace maintenance work.

This aircraft extension bit is intended for use in aerospace, aviation maintenance, and general metalworking applications where extended reach and precise hole sizing are required. The No. 49 wire size is a common specification in aircraft structural and sheet metal work. The bit meets NAS 907 Type B standards, making it appropriate for use in regulated aviation maintenance environments. Licensed A and P mechanics, sheet metal fabricators, and industrial maintenance technicians are the typical installers of this tool.

Key Features

• 135-degree split point with self-centering tip reduces walking and eliminates the need for a center punch
• 12-inch overall length provides extended reach for deep-cavity and confined-space drilling
• High-speed steel construction with oxide finish for wear resistance in general-purpose metal drilling
• Web-thinned, tapered web configuration reduces thrust and improves chip evacuation
• Straight cylindrical shank fits standard drill chucks without adapters
• Meets NAS 907 Type B standard for aerospace drilling applications

Compatibility

Designed as an OEM-specification aircraft extension drill bit for use in standard straight-shank drill chucks; sized to wire gauge No. 49 for aerospace sheet metal and structural drilling applications conforming to NAS 907 Type B.

Installation Notes

This bit is installed and operated by trained machinists, A and P mechanics, or sheet metal fabricators. Secure the straight cylindrical shank fully in the drill chuck before operation and verify chuck key is removed prior to powering the tool. Use appropriate cutting fluid or lubricant when drilling aluminum or steel to extend tool life and maintain hole tolerance. Inspect the cutting edges and point geometry before each use and discard if the split point or flutes show signs of wear or chipping.