Precision Twist Drill 5996181 Cobalt Screw Machine Drill Bit

Product Description

The PRECISION TWIST DRILL 5996181 is a cobalt screw machine length drill bit designed for high-performance drilling in hard and abrasive materials. Built to Series M41CO standards, this bit features a 135-degree split point for fast starts and reduced walking, a web-thinned tapered web for easier penetration, and a straight-cylindrical shank for solid chuck retention. At 0.157 inches (wire size #22) in diameter, it is sized for precision work in tight-tolerance applications. Licensed machinists, tool-and-die tradespeople, and HVAC or mechanical contractors drilling into hard metals rely on this grade of bit for reliable performance and extended tool life.

This bit is suited for drilling hard and difficult-to-machine materials including hardened steels, stainless, and other tough alloys where standard high-speed steel bits fail prematurely. The screw machine length profile — shorter than jobber length — provides increased rigidity and reduced deflection in drill press, CNC, and turret lathe setups. It is also commonly used in hand drilling applications where control and precision are critical. Its right-hand spiral flute design clears chips efficiently throughout the cut.

Key Features

• Cobalt construction (M41 material grade) for heat resistance and extended life in hard materials
• 135-degree split point reduces thrust and eliminates center punch requirement on most surfaces
• Web-thinned tapered web improves penetration and reduces cutting force
• Screw machine length body (overall length 2-1/8 inches) provides superior rigidity over jobber-length bits
• Straight-cylindrical shank compatible with standard drill chucks and collets
• Regular spiral flute with 2.5xD flute-to-diameter ratio for effective chip evacuation
• Meets ANSI specification standards for dimensional accuracy

Compatibility

Designed as a screw machine length replacement bit for #22 wire gauge (0.157 inch) drilling applications in hard and high-strength materials, compatible with standard straight-shank drill chucks across drill press, CNC turret, and hand-drill setups.

Installation Notes

Install the straight-cylindrical shank securely into the drill chuck and tighten fully before operation. Power down all equipment completely before changing bits. Use appropriate cutting fluid or coolant when drilling hard metals to preserve edge life, noting this bit does not support coolant-through delivery. Ensure workpiece is clamped securely to prevent movement during drilling.