Precision Twist Drill 5996548 Cobalt Screw Machine Drill Bit

Product Description

The PRECISION TWIST DRILL 5996548 is a cobalt screw machine length drill bit designed for high-performance drilling in hard and difficult-to-machine materials. It carries a 0.397 inch (Letter X) diameter and features a 135-degree split point for fast penetration and reduced walking on entry. The M42 cobalt steel construction provides heat resistance during high-speed operations. At 3-5/16 inches overall length with a 1-15/16 inch flute length, this stub-length geometry delivers added rigidity compared to jobber-length bits, making it a reliable choice for production drilling environments where deflection must be minimized.

This bit is suited for use in screw machine shops, CNC machining centers, drill presses, and hand-held drilling applications where hard ferrous and non-ferrous materials are encountered. The screw machine length format is common in automated and semi-automated production setups where short, stiff tooling reduces chatter and improves hole quality. It is appropriate for use by machinists, tool and die makers, and maintenance technicians working with hard stock.

Key Features

• M42 cobalt steel construction for heat resistance and extended tool life in hard materials
• 135-degree split point reduces thrust and eliminates center-punch requirement on most materials
• Web-thinned and tapered web configuration improves chip evacuation and reduces cutting load
• Screw machine (stub) length provides increased rigidity and reduced deflection versus jobber bits
• Straight-cylindrical shank fits standard drill chucks without additional tooling
• Right-hand spiral flute with 2.5xD flute-to-diameter ratio for consistent chip flow

Compatibility

Designed as an OEM-style replacement or direct-use cobalt drill bit for screw machine and production drilling applications requiring a 0.397 inch (Letter X) diameter in the 0.3500 to 0.4000 inch size range, per ANSI standards.

Installation Notes

Installation and use should be performed by qualified machinists or trained technicians familiar with rotating cutting tools. Ensure the drill chuck or collet is fully secured and the workpiece is properly clamped before beginning any drilling operation. Appropriate cutting fluid or coolant is recommended when drilling hard materials to extend tool life, noting this bit does not feature through-coolant capability. Follow applicable shop safety standards and machine manufacturer guidelines for spindle speed and feed rate selection.