Precision Twist Drill 5996119 Cobalt Aircraft Drill Bit

Product Description

The PRECISION TWIST DRILL 5996119 is a cobalt aircraft extension drill bit designed for drilling in hard metals, high-strength alloys, and tough aerospace-grade materials. It carries a wire gauge size of 5, which corresponds to a decimal diameter of 0.2055 inches. The 135-degree split point is self-centering and web-thinned, reducing the need for a center punch and lowering thrust during entry. The straw finish indicates heat treatment consistent with cobalt tooling. The straight-cylindrical shank measures 0.2055 inches in diameter and seats securely in standard drill chucks. This bit is part of the Series CO501-6 extended-length line and is suited for machinists, aircraft maintenance technicians, and metalworking tradespeople.

This drill bit is built for applications requiring extended reach beyond what a jobber-length bit can provide. The 2.5-inch flute length paired with a 6-inch overall length makes it well-suited for drilling through structural panels, tubing, and stacked materials where access is restricted. The right-hand cutting direction and spiral flute geometry provide efficient chip evacuation during continuous drilling. General-purpose cobalt construction handles both ferrous and non-ferrous materials, making it a versatile choice for sheet metal work, MRO operations, and fabrication tasks that demand dimensional accuracy.

Key Features

• Cobalt tool material for increased hardness and heat resistance compared to standard HSS
• 135-degree split point with web thinning for self-centering entry and reduced thrust
• Extended 6-inch overall length with 2.5-inch flute length for deep or restricted-access drilling
• Straw finish indicating cobalt heat treatment and surface hardness
• Straight-cylindrical shank at 0.2055 inches for compatibility with standard drill chucks
• Meets NAS 907 Type J standards for aircraft-grade tooling

Compatibility

Designed as an OEM-style replacement and general-use cobalt aircraft extension drill bit for applications conforming to NAS 907 Type J standards. Compatible with standard drill chucks accepting a 0.2055-inch straight-cylindrical shank.

Installation Notes

Installation and use of this drill bit should be performed by qualified machinists or aircraft maintenance technicians familiar with metal drilling procedures. Secure the shank fully in a properly rated drill chuck before operation, and ensure the workpiece is firmly clamped to prevent movement. Apply appropriate cutting fluid for the base material to extend tool life and maintain hole quality. Operate at feed rates and speeds appropriate for cobalt tooling in the target material.