Precision Twist Drill 6001385 Letter I Hss Aircraft Drill

Product Description

The PRECISION TWIST DRILL 6001385 is a Letter I high speed steel aircraft extension drill bit designed for deep-hole drilling in metal, aluminum, and composite materials. It features a 135-degree split point that is self-centering and web-thinned, reducing walking and cutting thrust on entry. The 12-inch overall length and 2.875-inch spiral flute length make it well-suited for reaching recessed or obstructed bore locations. The oxide finish provides mild corrosion resistance and helps reduce friction during the cut. This is a Series 502-12 bit built to NAS 907 Type B standards, used primarily by aviation maintenance technicians and metalworking tradespeople.

This drill bit is specified for aircraft and structural metalworking applications where standard-length bits cannot reach. The 12-inch extension body allows drilling through fuselage panels, structural members, and deep assemblies without repositioning the workpiece. The 0.272-inch diameter straight cylindrical shank is compatible with standard drill chucks and extension holders. Right-hand cutting direction and a 2-flute spiral design promote efficient chip evacuation in through-hole and blind-hole applications. General-purpose tool performance rating makes this suitable for production and field repair environments.

Key Features

• 135-degree split point with self-centering geometry reduces bit walking on curved or angled surfaces
• Web-thinned tapered web lowers cutting thrust and improves chip flow
• 12-inch overall length provides extension reach for deep or obstructed drilling locations
• High speed steel construction maintains edge integrity across a range of metal substrates
• Oxide finish reduces surface friction and provides light corrosion protection
• Built to NAS 907 Type B standard for aircraft maintenance and structural metalworking use

Compatibility

Designed as an OEM-style replacement or direct-use drill bit for applications requiring Letter I sizing at 0.272-inch diameter with a straight cylindrical shank, conforming to NAS 907 Type B specification.

Installation Notes

This drill bit is installed by aviation maintenance technicians, machinists, and metalworking tradespeople using standard drill chucks or extension holders rated for the shank diameter. Secure the workpiece firmly before drilling to prevent movement and ensure consistent hole geometry. Use appropriate cutting fluid or lubricant for the base material to extend tool life and improve hole finish. Inspect the split point and cutting edges before each use and replace the bit if chipping or wear is observed.