Chicago-Latrobe
Chicago-Latrobe 11130 135° NAS-Type Aircraft Extension Drill #6 HSS Black Oxide
High-speed steel aircraft extension drill with 135-degree split point and black oxide finish for deep-hole precision
- 135° split point starts drilling instantly without walking
- High-speed steel with black oxide resists wear and reduces friction
- 28° helix angle clears chips efficiently in deep holes
- Aircraft extension length reaches 2 1/2 in maximum drilling depth
- NAS-type design meets aerospace precision standards for wire-size #6 holes
Aircraft Extension Drill #6
The Chicago-Latrobe 11130 is a NAS-type aircraft extension drill sized at #6 with a 135-degree split point. Made from high-speed steel with a black oxide finish, it targets aviation maintenance technicians and metal fabrication shops needing extended reach in structural assemblies. The 28-degree helix supports chip evacuation in deep holes.
Installing the extension drill
The straight shank fits standard drill chucks and quick-change adapters without special tooling. The split point reduces walking on curved or hardened surfaces, so centre punching is often unnecessary. The black oxide coating can wear faster in abrasive alloys, and the extended length amplifies run-out if the chuck is not true. Coolant flow reaches the tip less easily at full 2 1/2 inch depth.
Limits of the 4xD geometry
The 4xD length-to-diameter ratio restricts practical use to through-holes or blind holes no deeper than 2 1/2 inches. Beyond that depth, chip packing and deflection increase rapidly in stainless or titanium. The 135-degree point angle is optimised for harder materials; softer aluminium may grab and require reduced feed rates. The high-speed steel substrate lacks the heat resistance of cobalt or carbide grades for sustained high-speed drilling.
Highlights
- 135° split point starts drilling instantly without walking
- High-speed steel with black oxide resists wear and reduces friction
- 28° helix angle clears chips efficiently in deep holes
- Aircraft extension length reaches 2 1/2 in maximum drilling depth
- NAS-type design meets aerospace precision standards for wire-size #6 holes
Specifications
| Brand | CHICAGO-LATROBE |
|---|
Questions about this item
How can I confirm the drill is cutting correctly after installing it?
A properly functioning bit produces clean, consistent chips and a round hole at the 135-degree split-point angle without wandering or excessive heat.
What comes in the package and what must I supply?
The box contains the Chicago-Latrobe 11130 #6 aircraft extension drill bit; you provide the drill motor, chuck or collet, cutting fluid and workpiece clamping.
When should I choose the #6 size over other available diameters?
Select the #6 bit when the job calls for a hole matching that specific wire-gauge diameter and a maximum drilling depth of 2 1/2 inches.
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