Cleveland C16683 5/16 Inch Cobalt Jobber Drill Bit

Product Description

The CLEVELAND C16683 is a jobber-length twist drill bit designed for demanding metal drilling applications. Built from M42 cobalt high-speed steel with a titanium nitride (TiN) coating, it delivers extended tool life when cutting through hard materials such as stainless steel, cast iron, and high-alloy steels. The 135-degree split point starts on contact without a center punch, reducing walking on hard surfaces. At 4.5 inches overall length with a 5/16-inch diameter, it fits standard drill chucks and magnetic drill presses used in HVAC fab, plumbing rough-in, and electrical panel work.

This bit is suited for trade professionals who regularly drill through structural steel, electrical enclosures, sheet metal assemblies, and mechanical room ironwork. The parabolic flute geometry evacuates chips efficiently during deep-hole drilling, reducing heat buildup and bit binding. A straight cylindrical shank accepts three-jaw chucks on corded drills, drill presses, and magnetic base drills common to mechanical and electrical contractors. The heavy-duty grade designation reflects suitability for production-volume drilling, not just occasional use.

Key Features

• M42 cobalt steel construction for heat resistance and edge retention in hard materials
• TiN coating reduces friction and extends tool life compared to uncoated HSS bits
• 135-degree split point for self-centering starts on hardened and coated surfaces
• Parabolic flute design promotes fast chip evacuation and reduced heat in deep holes
• Web-thinned, tapered web construction reduces thrust force required during drilling
• Meets ASME B94.11M and DIN 338 dimensional standards

Compatibility

Designed as a jobber-length replacement or production drill bit for use with any standard three-jaw drill chuck accepting a 5/16-inch straight cylindrical shank.

Installation Notes

Secure the shank fully in the chuck before drilling and confirm the bit runs true with no visible runout. Use cutting fluid or coolant when drilling stainless steel or other work-hardening alloys to preserve the cutting edge. Follow applicable OSHA and shop-safety requirements for eye protection and machine guarding when operating drill presses or magnetic base drills. Do not use this bit in hammer-drill mode.