Cleveland C15891 Jobber Drill Bit Wire 51 Cobalt

Product Description

The CLEVELAND C15891 is a cobalt jobber-length drill bit designed for demanding metal-cutting applications. Built to M42 high-speed steel cobalt specifications and finished with an oxide coating, it delivers extended tool life when drilling hard and abrasive materials, including superalloys. The bit is wire gauge size 51 with a decimal diameter of 0.0670 inches and an overall length of 2.0 inches. A 135-degree split point reduces walking on entry and lowers thrust force, making it well-suited for production drilling where hole location accuracy matters. Licensed machinists, tool-and-die tradespeople, and industrial maintenance techs are the primary users of this type of bit.

This bit is intended for drilling superalloys, stainless steel, and other hard ferrous materials where standard HSS bits wear prematurely. The fast spiral flute promotes chip evacuation from deep, small-diameter holes. With a straight-cylindrical shank diameter of 0.0670 inches and a shank length of 1-5/16 inches, it fits standard drill chucks and collet holders used in drill presses, CNC machines, and hand drills. It is manufactured to ASME B94.11M standards and carries an NAS specification designation, confirming dimensional and metallurgical compliance for aerospace and precision industrial work.

Key Features

• M42 cobalt steel construction for superior heat and wear resistance in hard-material drilling
• 135-degree split point reduces thrust and eliminates the need for a center punch on most surfaces
• Oxide coating provides lubricity and added surface hardness
• Fast spiral flute geometry promotes efficient chip removal from small-diameter holes
• Web-thinned, tapered web design maintains rigidity while reducing cutting resistance
• Meets ASME B94.11M dimensional standards with NAS specification designation

Compatibility

Designed as an OEM-style jobber-length drill bit for use in standard drill chucks and collet systems accepting a 0.0670-inch straight-cylindrical shank, suitable for primary workpiece materials classified as superalloys per Series 3780 application data.

Installation Notes

This bit is installed and used by machinists, tool-and-die technicians, and industrial maintenance professionals. Secure the straight shank firmly in the chuck or collet before operation and verify runout before drilling into finished or precision workpieces. Use appropriate cutting fluid or coolant when drilling superalloys to manage heat buildup, even though this bit does not support coolant-through delivery. Replace the bit when point geometry shows visible wear to avoid work hardening the base material.