Chicago-latrobe 11155 Aircraft Extension Drill Bit

Product Description

The CHICAGO-LATROBE 11155 is a high speed steel aircraft extension drill bit designed for deep-reach drilling applications in metal and aerospace-grade materials. Built to Series 912 standards, it carries a wire gauge size of 31, equivalent to 0.1200 inches in decimal diameter. The 135-degree split point is self-centering, reducing the need for a center punch and minimizing walking on entry. An oxide finish provides basic surface protection and lubricity during cutting. At 12 inches overall length, this bit gives technicians the reach needed for structural and airframe drilling where standard-length bits fall short.

This drill bit is suited for use in sheet metal fabrication, aircraft maintenance and repair, and general-purpose machining where extended reach is required. The straight-cylindrical shank accepts standard drill chucks without adapters. Right-hand spiral flutes with a tapered web configuration help evacuate chips cleanly during extended-depth passes. It is typically installed by aerospace maintenance technicians, metal fabricators, and industrial machinists working on ferrous and non-ferrous materials requiring tight-tolerance hole sizing.

Key Features

• 135-degree split point with self-centering geometry reduces walking and eliminates center-punch steps
• 12-inch overall length provides extended reach for deep or obstructed drilling locations
• High speed steel construction handles a wide range of metals in general-purpose applications
• Oxide finish adds surface lubricity and basic corrosion resistance during use
• Web-thinned, tapered web configuration reduces thrust and improves chip evacuation
• Diameter tolerance held to +0.0000 to -0.0005 inches for consistent, tight-tolerance hole sizing

Compatibility

Designed as a general-purpose aircraft extension drill bit conforming to NAS 907 Type B standards, suitable for use in standard drill chucks accepting a 0.1200-inch straight-cylindrical shank.

Installation Notes

This bit is installed by machinists, aerospace technicians, and metal fabricators using standard keyed or keyless drill chucks. Secure the workpiece before drilling and apply appropriate cutting fluid when working with harder alloys to extend tool life. Inspect the split point for wear or chipping before each use, as a damaged point will reduce self-centering accuracy and hole quality. Follow applicable shop safety standards and any relevant NAS or OEM procedures when drilling structural components.