Precision Twist Drill 6001250 Aircraft Extension Drill Bit

Product Description

The PRECISION TWIST DRILL 6001250 is a high speed steel aircraft extension drill bit designed for drilling in hard-to-reach locations where standard-length bits fall short. It carries a wire gauge size of #21, equivalent to 0.159 inches in diameter, and features a 135-degree split point that is self-centering and reduces walking on entry. The oxide finish provides light corrosion resistance during storage and use. With a 2.125-inch flute length and a 12-inch overall length, this bit delivers reach without sacrificing rigidity for its size class. It is part of PRECISION TWIST DRILL Series 501-12 and conforms to NAS 907 Type B standards.

This drill bit is suited for aerospace, aviation maintenance, sheet metal fabrication, and general metalworking applications where extended reach into tight or deep cavities is required. The straight-cylindrical shank seats securely in standard drill chucks, and the right-hand spiral flute design clears chips efficiently during through-hole drilling. It is commonly used by aviation maintenance technicians, machinists, and industrial maintenance professionals working on structural assemblies or equipment frames.

Key Features

• 135-degree split point is self-centering and reduces drill walk on entry
• 12-inch overall length provides extended reach for deep or obstructed work areas
• High speed steel construction handles general-purpose metal drilling
• Oxide finish offers light corrosion resistance
• Straight-cylindrical shank at 0.159 inches diameter fits standard chucks without adapters
• Web-thinned tapered web reduces thrust and improves cutting efficiency
• Conforms to NAS 907 Type B standard

Compatibility

Designed as an OEM-style replacement or direct-fit drill bit for applications requiring a #21 wire gauge, 0.159-inch diameter aircraft extension drill conforming to NAS 907 Type B specifications.

Installation Notes

This drill bit is installed and operated by machinists, aviation maintenance technicians, and metalworkers using standard drill chucks or extension holders rated for straight-cylindrical shanks. Secure the shank fully in the chuck before operation and verify chuck tightness to prevent slippage under load. Use appropriate cutting fluid for the base material being drilled to extend bit life and improve hole quality. Always wear eye protection and follow applicable shop safety procedures when operating rotary cutting tools.