Precision Twist Drill 5995991 Cobalt Drill Bit 5/64 in

Product Description

The PRECISION TWIST DRILL 5995991 is a screw machine length cobalt drill bit designed for drilling hard and difficult-to-machine materials. Built to the M40CO series specification, it features a 135-degree split point for fast penetration and reduced walking on contact. The straight-cylindrical shank seats securely in standard drill chucks, and the web-thinned, tapered web construction reduces cutting force. At 0.0781 inches (5/64 inch) in diameter with an overall length of 1-11/16 inches, this bit is suited for close-tolerance work in tight spaces. It meets ANSI standards and is rated for heavy-duty, high-performance applications.

This drill bit is intended for use in screw machine operations, production drilling, and general metalworking applications where hard or abrasion-resistant workpiece materials are encountered. The cobalt construction provides heat resistance that holds up under high-speed drilling without coolant, making it practical for shop floor and field use by machinists, maintenance technicians, and metalworking tradespeople. The short flute length of 11/16 inch and 2.5xD flute-to-diameter ratio are optimized for rigidity and chip evacuation in shallow-hole applications.

Key Features

• Cobalt tool material with coated finish for extended wear resistance in hard materials
• 135-degree split point reduces thrust and eliminates center-punching on most metals
• Web-thinned, tapered web lowers cutting resistance and improves chip flow
• Screw machine (stub) length provides added rigidity compared to jobber-length bits
• Right-hand spiral flute with regular helix for reliable chip evacuation
• Meets ANSI standards; rated heavy-duty and high-performance

Compatibility

Designed as an OEM-style replacement and production-use drill bit for standard straight-shank drill chucks compatible with 5/64 inch diameter tooling in screw machine and bench drill press applications.

Installation Notes

This bit is installed by a machinist or maintenance technician into any standard drill chuck accepting a straight-cylindrical shank. Ensure the chuck is fully tightened and the workpiece is firmly secured before operation. No coolant-through capability is present on this bit; use external cutting fluid when drilling hard or stainless alloys to extend tool life. Inspect the cutting edges before each use and replace if chipping or dulling is observed.