Precision Twist Drill 5995755 Cobalt Extension Drill Bit

Product Description

The PRECISION TWIST DRILL 5995755 is a cobalt aircraft extension drill bit designed for drilling through hard metals and alloys in demanding industrial and aerospace-maintenance applications. The 12-inch overall length provides reach into deep or confined areas where standard-length drill bits cannot access. The split-point, self-centering tip eliminates the need for a center punch on most materials, reducing setup time. A 135-degree point angle suits hard-metal drilling, and the straw finish results from the heat treatment process that enhances the cobalt steel. This bit is sized at 1/16 inch (0.0625 inch) diameter with a 7/8-inch flute length and is built to NAS 907 Type J standards.

This drill bit is suited for sheet metal fabrication, aircraft maintenance, and structural steel work where extended reach is required. The straight-cylindrical shank seats in standard drill chucks without an adapter. The 12-inch body length makes it practical for drilling through thick assemblies, deep flanges, or stacked material where a jobber-length bit would bottom out. General-purpose cobalt construction handles stainless steel, hardened alloys, cast iron, and other tough materials encountered in trade and light industrial environments. Licensed aircraft mechanics, fabricators, and millwrights are the primary users.

Key Features

• Cobalt tool steel construction for heat resistance and durability in hard-metal drilling
• 135-degree split point is self-centering, reducing or eliminating the need for a center punch
• 12-inch overall length provides extended reach into deep assemblies and structural cavities
• Straight-cylindrical shank fits standard drill chucks without adapters
• Straw finish indicates heat-treated cobalt steel for improved hardness retention
• Web-thinned, tapered-web design reduces thrust and improves chip evacuation
• Built to NAS 907 Type J standards for aircraft-grade quality

Compatibility

Designed as an OEM-style replacement or direct-use aircraft extension drill bit for applications requiring a 1/16-inch cobalt drill with a 12-inch overall length and straight-cylindrical shank, conforming to NAS 907 Type J specifications.

Installation Notes

Install the shank fully into a properly rated drill chuck and tighten securely before operation. Use appropriate cutting fluid or lubricant when drilling stainless steel or other hardened alloys to extend bit life and reduce heat buildup. Operate at speeds appropriate for cobalt bits in the target material; consult a standard speeds-and-feeds reference for the specific alloy. Wear eye protection and secure the workpiece before drilling.