Precision Twist Drill 5995984 Cobalt Aircraft Drill Bit

Product Description

The PRECISION TWIST DRILL 5995984 is a high-performance cobalt aircraft extension drill bit designed for drilling in tough, hard-to-reach applications. Built from cobalt steel with a straw finish, this bit handles harder workpiece materials where standard high-speed steel falls short. The 135-degree split point is self-centering and web-thinned, reducing walking on entry and lowering thrust requirements. At 6 inches overall length with a 2.125-inch flute length, it provides the reach needed for deep or extended-access drilling. It carries a 0.1695-inch decimal diameter corresponding to wire size No. 18 and features a straight-cylindrical shank of matching diameter. Spiral fluting with a right-hand cutting direction clears chips efficiently during through-hole operations. Licensed machinists, aerospace maintenance technicians, and industrial mechanics are the primary installers.

This bit is suited for aircraft, aerospace, and precision industrial applications where extension reach and material hardness demand cobalt construction. The CO501-6 series is built to NAS 907 Type J standards, making it appropriate for use on aluminum, stainless steel, titanium, and other difficult alloys common in aerospace and structural fabrication environments. The 4xD flute-length-to-diameter ratio supports chip evacuation in moderately deep holes without the deflection risk of longer extended bits. It ships as a single unit and is appropriate for both production drilling and field maintenance use.

Key Features

• Cobalt tool material with straw finish for heat and wear resistance in hard materials
• 135-degree split point with web thinning for self-centering entry and reduced thrust
• 6-inch overall length provides extended reach for aircraft and structural access drilling
• Straight-cylindrical shank at 0.1695 inches fits standard drill chucks without adapters
• Right-hand spiral fluting with tapered web for efficient chip clearance
• Meets NAS 907 Type J standards for aerospace-grade dimensional and performance requirements

Compatibility

Designed as an OEM-style replacement and direct-use drill bit for applications requiring a No. 18 wire size cobalt extension drill conforming to NAS 907 Type J specifications. Compatible with any standard drill chuck or drill motor accepting a 0.1695-inch straight-cylindrical shank.

Installation Notes

This drill bit is intended for use by machinists, aerospace maintenance technicians, and industrial mechanics operating hand drills, drill presses, or mag-base drills. Secure the straight-cylindrical shank fully in the chuck before operation and verify chuck runout is within acceptable limits to prevent premature edge wear. Use appropriate cutting fluid for the workpiece material, particularly when drilling stainless steel or titanium. Follow applicable workplace safety standards and equipment manufacturer guidelines for speed and feed selection.