Chicago-latrobe 11125 Aircraft Extension Drill Bit Hss

Product Description

The CHICAGO-LATROBE 11125 is a high speed steel aircraft extension drill bit engineered for deep-reach drilling in metal fabrication, aerospace maintenance, and structural applications. Built to Series 912 specifications, it carries a 135-degree split point that is self-centering and web-thinned, reducing the need for a center punch and minimizing walking on hard surfaces. The 0.228-inch diameter corresponds to wire size number 1. Oxide finish provides baseline corrosion resistance and reduces chip adhesion during cutting. The straight-cylindrical shank seats securely in standard drill chucks. Licensed trades and MRO technicians working on aircraft structures, long-reach boilermaker work, and HVAC sheet-metal penetrations will recognize this geometry.

This drill is suited for right-hand spiral-flute cutting in general-purpose ferrous and non-ferrous metals. The 12-inch overall length and 2.625-inch flute length make it the right choice when standard-length bits cannot reach a fastener location — common in aircraft skin repair, deep structural members, and confined mechanical spaces. The tapered web configuration maintains core strength along the full flute length. It conforms to NAS 907 Type B standards, making it appropriate for aerospace and defense maintenance environments where material traceability and dimensional tolerance matter.

Key Features

• 135-degree split point with web thinning for self-centering entry and reduced thrust force
• 12-inch overall length provides extended reach into deep or confined work areas
• High speed steel construction handles general-purpose ferrous and non-ferrous metals
• Oxide finish reduces friction and provides light corrosion resistance
• Straight-cylindrical shank fits standard 3-jaw drill chucks without adapters
• NAS 907 Type B compliant — suitable for aerospace and defense maintenance use
• Diameter tolerance held to +0.0000 to -0.0007 inches for consistent hole sizing

Compatibility

Designed as a general-purpose aircraft extension drill conforming to NAS 907 Type B, Series 912. Compatible with any standard drill press, magnetic drill, or hand drill with a chuck accepting a 0.228-inch straight-cylindrical shank.

Installation Notes

Installation and use should be performed by machinists, A and P mechanics, boilermakers, or sheet-metal technicians familiar with metal drilling procedures. Secure the workpiece fully before drilling to prevent rotation or shifting during the cut. Use appropriate cutting fluid for the base material to extend tool life and maintain hole-size tolerance. Inspect the split point and cutting edges before each use — a chipped or dulled point on a long-reach drill increases the risk of bit deflection in deep holes.