Chicago-latrobe 11151 Aircraft Extension Drill Bit 27 Hss

Product Description

The CHICAGO-LATROBE 11151 is a high speed steel aircraft extension drill bit designed for precision drilling in metal, composite, and structural materials common to aerospace and industrial maintenance applications. Built to Series 912 specifications, it features a 135-degree split point that is self-centering and web-thinned, reducing walking on entry and lowering the thrust needed to start a hole. The bit carries an oxide finish for basic lubricity and corrosion resistance during storage and use. The straight cylindrical shank measures 0.1440 inches in diameter, matching the wire size 27 designation. Flute length is 1.875 inches. Licensed HVAC, mechanical, and maintenance technicians routinely use extension-length drill bits like this one when standard-length bits cannot reach fastener locations in confined assemblies.

This drill bit is suited for production and maintenance drilling in ferrous and non-ferrous metals, light alloys, and similar materials where a 0.1440-inch diameter hole is required. The extended overall length of 12 inches allows access to recessed or deep locations that a jobber-length bit cannot reach. The right-hand spiral flute and two-flute geometry promote chip evacuation in through-hole drilling operations. General-purpose performance rating makes it appropriate for manual drill motors as well as drill press work at moderate speeds and feeds.

Key Features

• 135-degree split point with web thinning for self-centering entry and reduced thrust
• High speed steel construction for general-purpose metal drilling
• Oxide finish provides basic corrosion resistance and mild lubricity
• 12-inch overall length for access to recessed or deep drilling locations
• Straight cylindrical shank at 0.1440 inches for standard chuck compatibility
• Meets NAS 907 Type B standard for aircraft-quality drill geometry
• Diameter tolerance held to +0.0000 to -0.0007 inches for close-fit hole applications

Compatibility

Designed as a general-purpose aircraft extension drill bit conforming to NAS 907 Type B, compatible with standard three-jaw chucks and collet systems accepting a 0.1440-inch straight cylindrical shank.

Installation Notes

Installation of this drill bit requires a drill motor or drill press with a chuck rated for the shank diameter. Secure the shank fully in the chuck before applying power and verify the bit runs true before contact with the workpiece. When drilling metals, use appropriate cutting fluid to extend bit life and maintain hole tolerance. Follow applicable facility safety and PPE requirements when operating rotary cutting tools.