Chicago-latrobe 54117 Cobalt Drill Bit Letter R 0.3390 in

Product Description

The CHICAGO-LATROBE 54117 is a cobalt jobber length drill bit sized to Letter R (0.3390 inches) with a 135-degree split point and a titanium nitride (TiN) coating. Built to M42 cobalt material grade, this bit is engineered for heavy-duty drilling in tough materials where standard high-speed steel bits fail. The TiN coating extends cutting life by reducing friction and heat buildup at the tip. At 4-3/4 inches overall length with a 3-7/16 inch spiral flute, it delivers the reach and chip evacuation needed for production and maintenance drilling. Machinists, pipefitters, and maintenance techs reach for this bit when working through stainless steel and harder steel alloys.

This drill bit is suited for drilling stainless steel and steel in both shop and field environments. The right-hand spiral flute with web-thinned, tapered web geometry reduces walking and entry force on hard materials. The straight-cylindrical shank seats securely in standard drill chucks without adapters. It is used in manual drill presses, CNC setups, and heavy-duty handheld drills wherever precise, clean holes are required in ferrous and corrosion-resistant metals. Series 2550 designates this as a high-performance production-class bit conforming to DIN 338 and NAS 907 Type J standards.

Key Features

• M42 cobalt steel construction for heat resistance in hard and abrasive materials
• 135-degree split point reduces walking and lowers thrust required at entry
• Titanium nitride (TiN) coating extends tool life and resists wear
• Web-thinned tapered web improves chip flow and reduces heat at the cutting edge
• Right-hand regular spiral flute evacuates chips cleanly from deep holes
• Straight-cylindrical shank fits standard 3-jaw chucks without reduction sleeves

Compatibility

Designed for drilling stainless steel and steel workpieces. Compatible with standard drill chucks accepting a 0.3390-inch straight-cylindrical shank. Conforms to DIN 338 and NAS 907 Type J specifications.

Installation Notes

Secure the bit fully in the chuck and verify runout before drilling. Use appropriate cutting fluid or coolant when drilling stainless steel to manage heat and extend bit life, even though this bit does not support through-coolant delivery. Allow the split point to self-center before applying full feed pressure. Inspect the cutting edges for chipping or wear after extended use in hard materials and replace the bit before edge degradation causes oversized holes.