Precision Twist Drill 5995938 Screw Machine Drill Bit

Product Description

The PRECISION TWIST DRILL 5995938 is a cobalt screw machine length drill bit designed for high-performance drilling in hard and difficult-to-machine materials. It carries a 135-degree split point angle with web thinning, which reduces walking on entry and lowers the thrust needed to start the cut. The straight-cylindrical shank fits standard drill chucks without adapters. At 2.75 inches overall length with a 1.5625-inch flute length, this stub-length geometry delivers added rigidity compared to jobber-length bits, making it well suited for applications where chatter and deflection are concerns. Cobalt construction provides heat resistance beyond standard high-speed steel, extending tool life in demanding cuts.

This drill bit is built for drilling hard metals, alloys, and other abrasive workpiece materials where standard HSS bits wear prematurely. The screw machine length format is common in production shop environments, CNC setups, and bench drill press work where shorter overhang improves rigidity and dimensional accuracy. The right-hand spiral flute evacuates chips efficiently during through-hole and blind-hole operations. The M40CO series designation indicates a cobalt-grade alloy formulated for heavy-duty cutting duty. This bit is used by machinists, tool and die technicians, and industrial maintenance trades.

Key Features

• Cobalt M40 grade construction for extended tool life in hard materials
• 135-degree split point with web thinning reduces walking and entry thrust
• Screw machine (stub) length provides greater rigidity than jobber-length bits
• Right-hand cut with regular spiral flute for efficient chip evacuation
• Straight-cylindrical shank fits standard drill chucks without adapters
• Tapered web configuration supports cutting edge strength throughout flute length
• Meets ANSI standards for dimensional accuracy and geometry

Compatibility

Designed as a screw machine length cobalt drill bit for use with standard drill chucks, drill presses, CNC machining centers, and hand-held power drills where a straight-cylindrical shank is accepted. Intended for use in hard and abrasive workpiece materials per ANSI specification.

Installation Notes

Installation and use should be performed by qualified machinists or trades personnel familiar with metalworking drill bit operation. Secure the shank fully in the chuck and verify runout before drilling. Always power down and de-energize the machine before changing or inspecting bits. Use cutting fluid or coolant appropriate to the workpiece material to preserve tool life and maintain safe operating temperatures; this bit does not support coolant-through delivery.