Chicago-latrobe 47852 Cobalt Jobber Drill 4.20mm 135 Deg

Product Description

The CHICAGO-LATROBE 47852 is a cobalt jobber-length drill bit engineered for high-performance drilling in demanding materials. It features a 4.20 mm (0.1654 inch) diameter, a 135-degree split point for self-centering starts and reduced walking, and a gold straw coating applied over a cobalt steel substrate. The two-flute regular spiral design promotes efficient chip evacuation. Overall length is 75.00 mm (2.9528 inches) with a 43.00 mm (1.6929 inch) flute length. Built to NAS 907 Type B standards, this bit is classified as heavy duty and is part of the Series 550ASP line intended for rigorous production and maintenance drilling applications.

This drill bit is suited for metalworking professionals, maintenance technicians, and fabricators who regularly drill stainless steel, hardened metals, and other high-strength alloys. The cobalt composition and split-point geometry reduce heat buildup and cutting resistance in materials that would quickly dull standard high-speed steel bits. Right-hand cutting with a straight cylindrical shank makes it compatible with standard drill chucks in both handheld and drill-press setups. It is a practical choice in industrial, HVAC fabrication, plumbing rough-in, and general metal trade work where tool longevity in tough materials matters.

Key Features

• Cobalt steel construction with straw coating for extended tool life in stainless steel and hardened materials
• 135-degree split point reduces thrust, self-centers on entry, and eliminates the need for a center punch in most applications
• Web-thinned, tapered-web design lowers cutting resistance and improves chip clearance
• Meets NAS 907 Type B specification for dimensional and performance consistency
• Regular spiral flute geometry balances chip evacuation with rigidity across the 43.00 mm flute length
• Straight cylindrical shank sized at 4.20 mm (0.1654 inch) fits standard keyed and keyless chucks

Compatibility

Designed as a heavy-duty OEM-style jobber drill for use in standard drill chucks accepting a 4.20 mm straight shank. Primary workpiece materials are stainless steel and hardened metals per Series 550ASP application guidelines.

Installation Notes

Installation of this drill bit is performed by machinists, metalworkers, and licensed trade technicians using a compatible drill press, magnetic drill, or handheld power drill. Secure the straight shank fully in the chuck and verify runout before beginning production drilling. Use appropriate cutting fluid or coolant when drilling stainless steel or hardened alloys to manage heat and preserve cutting edge life. Inspect the cutting edges before each use and replace the bit if chipping or dulling is observed.