Chicago-latrobe 54120 Jobber Drill Bit Letter U Cobalt

Product Description

The CHICAGO-LATROBE 54120 is a jobber-length drill bit sized to Letter U (0.3680 inches decimal) with a 135-degree split point and a titanium nitride (TiN) coating over an M42 cobalt high-speed steel body. It is engineered for high-performance drilling in stainless steel and hard steels where standard HSS bits lose edge integrity too quickly. The overall length is 5 inches, the flute length is 3.625 inches, and the straight-cylindrical shank measures 0.3680 inches in diameter. The web-thinned, tapered web design reduces thrust load and improves chip evacuation. Licensed HVAC, plumbing, mechanical, and electrical contractors reach for this bit when drilling stainless sheet metal, structural members, or hard alloy brackets in the field or shop.

This bit is suited for production and maintenance drilling in ferrous metals, with primary applications in stainless steel and carbon steel fabrication. The regular-spiral, two-flute geometry paired with the TiN coating extends tool life significantly in repetitive hole cycles. It is a single-piece, individually packaged bit conforming to DIN 338 and NAS 907 Type J standards, making it appropriate for any trade application that requires certified dimensional accuracy in drilled holes. The Series 2550 designation places it in the heavy-duty grade product family.

Key Features

• M42 cobalt HSS construction for heat resistance in hard and stainless steels
• Titanium nitride (TiN) coating reduces friction and extends cutting edge life
• 135-degree split point with web thinning reduces walking and lowers thrust requirements
• Two-flute regular spiral design promotes consistent chip clearance in deep holes
• Straight-cylindrical shank fits standard drill chucks without adapters
• Meets DIN 338 and NAS 907 Type J dimensional standards

Compatibility

Designed for use in standard drill chucks accepting a 0.3680-inch straight-cylindrical shank. Optimized for drilling stainless steel and carbon steel per Series 2550 heavy-duty jobber-length specifications.

Installation Notes

This bit is installed and operated by any trade professional using a corded or cordless drill press, handheld drill, or magnetic base drill. Always secure the workpiece before drilling and use appropriate cutting fluid when drilling stainless steel to manage heat buildup. Inspect the cutting edges before each use and replace the bit if chipping or dulling is observed. Proper RPM selection for the material and bit diameter is critical to achieving rated tool life.