Precision Twist Drill 5996544 Cobalt Screw Machine Drill Bit

Product Description

The PRECISION TWIST DRILL 5996544 is a cobalt screw machine length drill bit designed for high-performance drilling in hard and tough materials. Built to the M42CO series specification, it features a 135-degree split point for fast penetration and reduced walking on entry. The straight-cylindrical shank seats securely in standard drill chucks and machine spindles. At 0.386 inches (Letter W) in diameter with a 3.25-inch overall length and a 1.875-inch flute length, this bit is sized for short-reach, high-accuracy work in drill presses, CNC machines, and screw machine setups. Web-thinned and tapered web construction reduces thrust requirements and improves chip evacuation.

This bit is suited for drilling hard metals, alloy steels, stainless steel, and other materials that demand heat-resistant tooling. The M42 cobalt steel construction maintains hardness and edge life at elevated cutting temperatures, making it appropriate for production environments where tool life and hole quality are priorities. Machinists, tool-and-die workers, and maintenance technicians working with hard or abrasive workpiece materials will find this a practical choice for stub-length applications where rigidity matters.

Key Features

• M42 cobalt steel construction for heat resistance and extended tool life in hard materials
• 135-degree split point reduces thrust and minimizes bit walking on entry
• Web-thinned, tapered web design improves chip flow and lowers cutting resistance
• Screw machine (stub) length provides increased rigidity compared to jobber-length bits
• Right-hand spiral flute with 2.5xD flute-to-diameter ratio for efficient chip evacuation
• Straight-cylindrical shank compatible with standard three-jaw chucks and collet holders
• Meets ANSI standards for dimensional accuracy and performance consistency

Compatibility

Designed as an OEM-style replacement or direct substitute for Letter W screw machine length drill bits in M42 cobalt grade; fits any drill press, CNC machining center, or hand-held drill with a chuck or collet sized for a 0.386-inch straight-cylindrical shank.

Installation Notes

Install and remove this bit only with the machine fully powered down and the spindle at a complete stop. Secure the shank fully in the chuck or collet to the recommended engagement depth before tightening. Use appropriate cutting fluid or coolant for hard material applications to extend edge life, even though this bit does not support through-coolant delivery. Follow applicable shop safety practices and machine manufacturer guidelines for speed and feed selection.