Precision Twist Drill 5995858 Cobalt Drill 9/64 in

Product Description

The PRECISION TWIST DRILL 5995858 is a cobalt aircraft extension drill bit designed for drilling through hard metals and alloys in aerospace, automotive, and industrial maintenance applications. Built to Series CO500-6 standards, it features a 135-degree split point that is self-centering, reducing the need for a center punch and minimizing walking on hard surfaces. The straw finish indicates heat-treated cobalt construction, offering improved wear resistance and heat tolerance compared to standard high-speed steel bits. With a 9/64 inch (0.1406 inch decimal) diameter and 1-3/4 inch flute length, this bit is suited for precise, controlled drilling in tight or deep-reach situations. It is sold individually.

This drill bit is intended for professional use in sheet metal fabrication, aircraft structural work, and general-purpose industrial drilling where hard or abrasive materials are encountered. The 6-inch overall length provides extended reach into recessed areas or through stacked material. The right-hand spiral flute geometry and web-thinned, tapered web configuration promote efficient chip evacuation and reduce axial thrust during drilling. It is compatible with standard drill chucks and collets accepting a straight cylindrical shank in 9/64 inch diameter.

Key Features

• Cobalt tool material for superior heat and wear resistance when drilling hard metals
• 135-degree split point is self-centering, eliminating pilot holes on most applications
• 6-inch overall length provides extended reach for aircraft and deep-cavity drilling
• Straw finish indicates tempered cobalt construction for extended tool life
• Web-thinned tapered web reduces cutting resistance and axial thrust
• Meets NAS 907 Type J standards for aircraft-grade drilling applications

Compatibility

Designed as an OEM-style replacement or direct-use cobalt extension drill bit for professional drilling applications requiring a 9/64 inch straight cylindrical shank. Conforms to NAS 907 Type J standards as noted in the product specifications.

Installation Notes

This drill bit is installed by machinists, aircraft maintenance technicians, and industrial trades professionals using standard keyed or keyless drill chucks rated for the shank diameter. Ensure the chuck is fully tightened and the workpiece is securely clamped before drilling. Use appropriate cutting fluid when drilling hardened alloys to reduce heat buildup and extend bit life. Follow applicable shop safety standards and PPE requirements when operating rotary cutting tools.