Precision Twist Drill 5995980 Cobalt Extension Drill Bit

Product Description

The PRECISION TWIST DRILL 5995980 is a high-performance cobalt aircraft extension drill bit designed for demanding drilling applications in hard and abrasive materials. Built to NAS 907 Type J standards, it features a 135-degree split point with a self-centering tip that eliminates the need for a center punch and reduces walking on entry. The two-flute spiral design with web thinning improves chip evacuation and reduces thrust. At 6 inches overall length, the extended reach makes it well suited for accessing recessed or confined bore locations that standard-length bits cannot reach.

This drill bit is used in aerospace, metalworking, and general industrial applications where extended reach and material toughness are required. The No. 1 wire size (0.228 inches diameter) fits common production drilling tasks in steel, stainless, titanium, and other high-strength alloys. The straw finish indicates heat treatment and provides a degree of surface hardness. Machinists, tool-and-die technicians, aircraft maintenance professionals, and skilled fabricators are the primary installers and users of this bit.

Key Features

• 135-degree split point with self-centering geometry reduces walking and eliminates center-punching on most surfaces
• Cobalt tool material resists heat buildup and maintains edge hardness in stainless, titanium, and high-strength alloys
• Web-thinned tapered web lowers drilling thrust and improves chip flow
• Extended 6-inch overall length provides reach into recessed or obstructed bore locations
• Right-hand spiral flutes with 2.625-inch flute length for efficient chip evacuation
• Meets NAS 907 Type J standard for aerospace-grade drill bit performance

Compatibility

Designed as an OEM-style replacement or direct-use drill bit compatible with standard drill chucks and extension holders accepting a 0.228-inch straight-cylindrical shank. Part of the PRECISION TWIST DRILL Series CO501-6 aircraft extension line.

Installation Notes

Secure the shank fully in the drill chuck before operation and verify chuck key is removed prior to starting the spindle. Use appropriate cutting fluid or coolant for ferrous and high-strength alloy drilling to extend bit life and prevent heat damage. Operate at recommended surface footage for cobalt tooling in the workpiece material. Inspect the cutting edges before each use and replace when chipping or dulling is observed.