Precision Twist Drill 6001251 Letter R Hss Extension Drill

Product Description

The PRECISION TWIST DRILL 6001251 is a Letter R aircraft extension drill bit engineered for deep-hole drilling applications where standard-length bits cannot reach. Built from high speed steel (HSS) with an oxide finish, this bit features a 135-degree split point that is self-centering and eliminates the need for a center punch on most materials. The extended 12-inch overall length and 3.4375-inch spiral flute accommodate thick workpieces, structural members, and assemblies common in aerospace, aviation maintenance, and heavy fabrication. Licensed tradespeople and MRO technicians working under NAS 907 Type B requirements will find this bit spec-compliant for those applications.

This drill bit is suited for use in residential and commercial construction, aviation maintenance, and industrial fabrication environments where extended reach is required. The 0.339-inch diameter straight-cylindrical shank fits standard three-jaw drill chucks without adapters. The two-flute spiral design with web-thinned, tapered web configuration promotes efficient chip evacuation in steel, aluminum, and other ferrous and non-ferrous materials. General-purpose tool performance rating makes it appropriate for a wide range of drilling tasks in sheet metal, structural steel, and composite assemblies.

Key Features

• 135-degree split point is self-centering for accurate hole starts without center punching
• 12-inch overall length provides extended reach into deep cavities and structural assemblies
• High speed steel construction withstands heat generated in continuous drilling operations
• Oxide finish improves lubricity and surface hardness for longer service life
• Web-thinned, tapered web reduces feed force and minimizes heat buildup at the cutting tip
• Meets NAS 907 Type B standards for aircraft and aerospace drilling applications

Compatibility

Designed as an OEM-style replacement and general-use aircraft extension drill bit for applications requiring a Letter R (0.339-inch) diameter hole with an extended 12-inch reach in standard three-jaw drill chucks.

Installation Notes

Aircraft extension drill bits of this type are typically installed and operated by licensed aviation maintenance technicians, machinists, or qualified tradespeople. Secure the straight-cylindrical shank firmly in a drill chuck rated for the intended RPM before use. Ensure the workpiece is clamped or fixtured to prevent movement during drilling. Apply appropriate cutting fluid for ferrous materials to extend bit life and maintain hole quality.