Precision Twist Drill 5998658 Drill Bit Letter C Hss

Product Description

The PRECISION TWIST DRILL 5998658 is a jobber-length twist drill bit sized to Letter C (0.2420 inches) and ground to a 118-degree standard point angle. Manufactured from high speed steel with a steam oxide coating, it delivers dependable performance across a broad range of metal-cutting applications. The spiral flute geometry and web-thinned, tapered web construction promote efficient chip evacuation and reduce thrust during entry. With an overall length of 4 inches and a 2-3/4-inch flute length, this bit fits standard drill chucks and is suited for bench drills, hand-held power drills, and CNC drilling operations. It is a general-purpose tool installed by machinists, maintenance technicians, and fabricators.

This bit is designed for drilling steel, stainless steel, cast iron, non-ferrous metals, superalloys, and titanium. It is applicable in production shops, maintenance and repair operations, and field fabrication environments where a reliable, general-purpose jobber-length drill is required. The 0.2420-inch straight-cylindrical shank fits standard Jacobs-style chucks and collet systems without modification. The Series R10A-R15A-R18A designation covers the range this bit belongs to, and it conforms to ANSI and NAS 907 standards, making it suitable for aerospace and industrial fastener hole preparation.

Key Features

• Letter C size at 0.2420 inches decimal equivalent for precise hole sizing
• 118-degree standard point angle for general-purpose metal drilling
• High speed steel construction with steam oxide coating for wear resistance and corrosion inhibition
• Web-thinned, tapered web reduces cutting thrust and improves chip flow
• Regular spiral flute with 11xD flute-to-diameter ratio for efficient chip evacuation
• Conforms to ANSI and NAS 907 specifications for aerospace and industrial applications

Compatibility

Designed as a general-purpose jobber-length drill bit compatible with standard straight-shank drill chucks and collet holders accepting a 0.2420-inch shank diameter. Suitable for use in drill presses, hand-held power drills, and CNC machining centers. Rated for primary workpiece material codes P, M, K, N, and S covering steel, stainless steel, cast iron, non-ferrous metals, and superalloys.

Installation Notes

Installation is performed by machinists, maintenance technicians, or fabricators. Secure the straight-cylindrical shank firmly in the chuck or collet before operation and verify runout is within acceptable limits. Always wear appropriate eye protection and ensure the workpiece is clamped securely before drilling. Coolant-through is not supported on this bit; use external cutting fluid when drilling hard or heat-sensitive materials.