Chicago-Latrobe 47712 3/16" Cobalt TiN 135° Split Point Jobber Drill Bit

Precision 3/16" Cobalt Drill Bit

The Chicago-Latrobe 47712 is a jobber-length drill bit manufactured from cobalt high-speed steel with a titanium nitride coating. It features a 135-degree split point designed for self-centering and reduced thrust during operation. The fractional 3/16 inch size provides a decimal equivalent of .1875 inches for precise holemaking. This accessory targets professionals and serious DIY users drilling hard metals such as stainless steel and titanium alloys.

Upgrade From Standard High-Speed Steel Bits

This bit replaces general-purpose high-speed steel drills when the workpiece material causes rapid dulling or excessive heat buildup. The cobalt substrate maintains hardness at higher temperatures, while the TiN coating reduces friction and extends cutting life. The jump is worth it for repetitive drilling in abrasive or work-hardening alloys where standard bits fail prematurely. It is not suited for wood, plastics, or soft non-ferrous metals where the aggressive split point may grab or chip the material.

Sustained Cutting In Hard Alloys

Under continuous load the cobalt matrix resists softening better than conventional HSS, allowing the cutting edges to stay sharp through multiple holes. The straw-bronze surface treatment helps identify the tool and signals the presence of the wear-resistant coating. With zero coolant holes the bit relies on external flood or mist cooling for deep-hole work. The 135-degree geometry produces thicker chips that evacuate efficiently in tough materials but may require peck cycles in deeper applications.