Precision Twist Drill 5995948 Cobalt Screw Machine Drill Bit

Product Description

The PRECISION TWIST DRILL 5995948 is a cobalt screw machine length drill bit designed for high-performance drilling in hard and abrasive materials. Built to ANSI standards, this 25/64 inch (0.3906 inch) diameter bit features a 135-degree split point for fast engagement and reduced walking on entry. The spiral flute geometry runs at a 2.5xD ratio, promoting efficient chip evacuation during drilling. The web-thinned, tapered web construction lowers thrust requirements on tough workpieces. It is suited for machinists, tool-and-die professionals, and maintenance technicians working with hard steels, stainless, and similar difficult-to-machine materials.

The M40CO series screw machine drill bit is intended for use in drill presses, CNC machining centers, and manual lathes where a stub-length bit provides added rigidity over jobber-length alternatives. The compact screw machine length — 3.25 inches overall — reduces deflection in short-reach applications. This bit is appropriate for production environments and job-shop applications requiring consistent, repeatable hole quality in hard or work-hardened materials. The straight cylindrical shank accepts standard drill chucks without modification.

Key Features

• Cobalt construction rated for drilling hard and abrasive materials including high-alloy and stainless steels
• 135-degree split point reduces thrust and eliminates center-punch requirements on most surfaces
• Web-thinned tapered web lowers cutting resistance and improves chip clearance
• Screw machine (stub) length at 3.25 inches overall provides superior rigidity over standard jobber bits
• Regular spiral flute with 2.5xD flute-to-diameter ratio for effective chip evacuation
• Meets ANSI standards; M40 material grade for heavy-duty service

Compatibility

Designed as an OEM-style replacement or upgrade for screw machine length drill bits in the 0.3500 to 0.4000 inch decimal diameter range, compatible with any standard drill chuck accepting a straight cylindrical shank.

Installation Notes

Installation and use of this bit should be performed by machinists or qualified trade professionals familiar with machine tool operation. Secure the shank fully in the drill chuck and verify runout before beginning a cut. Always power down and de-energize the machine before changing tooling. Follow applicable ANSI B11 machine tool safety standards and shop-specific lockout/tagout procedures when servicing or changing drill bits in production equipment.