Precision Twist Drill 5996086 Cobalt Drill Bit No 40

Product Description

The PRECISION TWIST DRILL 5996086 is a cobalt aircraft extension drill bit designed for drilling in hard and abrasion-resistant materials where standard high-speed steel bits fall short. Built to Series CO501-6 specifications, it carries a wire gauge size of No. 40 with a decimal diameter of 0.098 inches and a 135-degree split point that self-centers on contact, reducing the need for a center punch. The straw finish indicates a heat-treated cobalt steel construction suited for tough alloys. At 6 inches overall length with a 1.375-inch flute, this extended-reach bit gives technicians and machinists access to recessed or hard-to-reach hole locations in sheet metal, aerospace structures, and similar assemblies.

This drill bit is intended for professional use in aerospace, aviation maintenance, HVAC fabrication, electrical rough-in, and general metalworking applications where an extended reach is required. The straight-cylindrical shank seats securely in standard drill chucks and drill motors without special adapters. Its two-flute right-hand spiral design clears chips efficiently in through-hole and blind-hole work. The self-centering split point and web-thinned, tapered web configuration reduce thrust force and walking on entry, making it well suited for hand-held drill motor use on structural panels or enclosures.

Key Features

• Cobalt tool steel construction handles hard alloys, stainless steel, and heat-resistant materials
• 135-degree split point with web thinning self-centers and reduces entry thrust
• 6-inch overall length provides extended reach into recessed or confined workspaces
• Straw finish indicates heat-treated cobalt steel for extended tool life
• Straight-cylindrical shank at 0.098 inches fits standard chucks without adapters
• Meets NAS 907 Type J standards for aerospace and precision drilling applications

Compatibility

Designed as an OEM-style replacement or direct-use cobalt extension drill bit for applications requiring a No. 40 wire gauge hole diameter in accordance with NAS 907 Type J standards. Fits any standard drill chuck accepting a 0.098-inch straight-cylindrical shank.

Installation Notes

Installation of this drill bit is performed by machinists, maintenance technicians, or sheet metal workers using a standard drill motor or drill press. Secure the straight-cylindrical shank fully in the chuck before operation and verify chuck key is removed prior to starting the tool. Use cutting fluid or coolant when drilling hard alloys to preserve bit life and maintain dimensional accuracy. Follow applicable facility safety protocols and wear appropriate eye protection during all drilling operations.