Chicago-latrobe 46721 Cobalt Jobber Drill Bit No 51

Product Description

The CHICAGO-LATROBE 46721 is a cobalt jobber length drill bit in wire gauge size No. 51, measuring 0.0670 inches in diameter. Built to Series 550 specifications, it features a 135-degree split point and a gold oxide coating for heat and wear resistance. The M42 cobalt steel construction handles high-hardness materials where standard high-speed steel bits fall short. At 2 inches overall length with a 1-inch spiral flute, this bit delivers controlled chip evacuation and consistent hole geometry. It is designed for right-hand cutting with a straight-cylindrical shank and web-thinned tapered web for reduced thrust on entry.

This drill bit is rated for high-performance drilling in titanium and other hard or abrasive metals. The cobalt M42 grade makes it a standard choice in aerospace, defense, and precision fabrication shops where NAS 907 Type J compliance is required. The gold oxide finish provides lubricity and extended tool life in interrupted cuts and stack drilling. It suits hand-held drill motors, drill presses, and CNC drilling operations where small-diameter, tight-tolerance holes are needed in challenging workpiece materials.

Key Features

• M42 cobalt steel construction for drilling titanium, hardened steel, and other high-strength alloys
• 135-degree split point reduces walking and lowers thrust force on entry
• Gold oxide coating improves lubricity and extends service life in hard materials
• Web-thinned tapered web minimizes heat buildup and cutting resistance
• Meets DIN 338 and NAS 907 Type J standards for aerospace and precision applications
• Right-hand spiral flute with regular spiral type for efficient chip removal

Compatibility

Designed as an OEM-style replacement or direct-use jobber drill bit for applications requiring wire gauge size No. 51 (0.0670 inches) in Series 550 heavy-duty cobalt construction per NAS 907 Type J and DIN 338 specifications.

Installation Notes

This bit is installed and operated by machinists, tool-and-die technicians, aerospace fabricators, and precision metalworkers. Before use, confirm the spindle and chuck are clear of debris and that the shank is fully seated and centered. Use appropriate cutting fluid or coolant when drilling titanium or hardened alloys to manage heat at the cutting edge. Operate at manufacturer-recommended speeds and feeds for the workpiece material to avoid premature edge wear or bit failure.