Precision Twist Drill 5996137 Cobalt Drill Bit Letter E

Product Description

The PRECISION TWIST DRILL 5996137 is a screw machine length cobalt drill bit sized at Letter E (0.25 inches decimal), designed for drilling into hard and tough materials where standard high-speed steel bits fall short. Built to the M40CO series specification, it features a 135-degree split point that reduces walking and cuts through workpieces with less feed pressure. The web-thinned, tapered web design improves chip evacuation and cutting efficiency. At 2.5 inches overall length with a 1.375-inch flute length, this short-length geometry provides added rigidity and reduced deflection in production drilling applications. It conforms to ANSI standards and is rated for heavy-duty use.

This bit is suited for metalworking and fabrication environments where hard or abrasive workpiece materials are common. The screw machine length profile makes it a practical choice for drill press work, CNC operations, and manual machining where a shorter, stiffer bit is preferred over jobber length. Right-hand cut with a straight-cylindrical shank allows it to seat directly in standard chucks without adapters. It is a single-piece package intended for professional machinists, maintenance technicians, and fabricators working with harder alloys and difficult-to-machine materials.

Key Features

• Cobalt construction (M40 material grade) provides heat and wear resistance for drilling hard materials
• 135-degree split point reduces bit walking and lowers required feed force
• Web-thinned tapered web promotes efficient chip clearing and reduced thrust load
• Screw machine length (2.5 inches OAL) delivers increased rigidity and reduced deflection vs. jobber length
• Straight-cylindrical shank fits standard drill chucks without modification
• ANSI-compliant, heavy-duty grade for production and repeat-use applications

Compatibility

Designed as an OEM-style replacement or direct-use screw machine drill bit for applications involving hard workpiece materials as designated by ANSI standards within the M40CO series.

Installation Notes

This bit is installed and operated by machinists or qualified trade technicians using standard drill press, lathe, or CNC equipment. Secure the straight shank firmly in a calibrated chuck before use and verify chuck runout is within acceptable tolerance to avoid premature wear. Use appropriate cutting fluid or coolant when drilling hard materials to extend tool life, noting that this bit does not support coolant-through delivery. Always wear appropriate eye protection and follow shop safety protocols when operating drilling equipment.