Chicago-latrobe 50821 Screw Machine Drill Bit 0.375 in Cobalt

Product Description

The CHICAGO-LATROBE 50821 is a screw machine length cobalt drill bit designed for high-performance drilling in ferrous and hard materials. Built from M42 cobalt high-speed steel, it delivers heat and wear resistance that standard HSS bits cannot match in demanding production environments. The 135-degree split point reduces walking on entry and lowers thrust force required at the drill press or CNC spindle. At 0.375 inches in diameter with an overall length of 3.125 inches and a flute length of 1.8125 inches, this stub-length bit provides added rigidity compared to jobber-length equivalents. Web thinning and a parallel web configuration further reduce cutting resistance, making this bit suitable for continuous or high-cycle drilling operations in steel and cast iron.

The 50821 is used in machine shops, fabrication facilities, and production environments where hole quality and bit longevity are priorities. Its screw machine (stub) length is the standard choice for drill press, turret lathe, and CNC machining center applications where rigidity matters and shorter overhang reduces deflection. Primary target materials are cast iron and steel, making it appropriate for HVAC equipment fabrication, structural steel work, and general metalworking. The right-hand spiral flute and straight-cylindrical shank ensure compatibility with standard drill chucks and collet holders used across these trades.

Key Features

• M42 cobalt steel construction provides superior heat resistance for continuous cutting in hard metals
• 135-degree split point reduces bit walking and lowers entry thrust in steel and cast iron
• Screw machine (stub) length of 3.125 inches overall for maximum rigidity and reduced deflection
• Web-thinned parallel web reduces cutting resistance during high-cycle operations
• Diameter tolerance of +0.0000 to -0.0010 inches ensures consistent, accurate hole sizing
• ISO standard compliance for use in quality-controlled production environments

Compatibility

Designed for use in standard drill chucks and collet holders accepting straight-cylindrical shanks. Rated for drilling cast iron and steel. Fits Series 559 tooling configurations per CHICAGO-LATROBE specifications.

Installation Notes

Installation and use of this drill bit should be performed by machinists or qualified trade professionals familiar with rotating cutting tools and machine safety. Ensure the workpiece is securely clamped and the spindle is stopped completely before securing or removing the bit from the chuck. Use appropriate cutting fluid for steel and cast iron to extend tool life and maintain hole quality. Follow machine manufacturer guidelines for RPM and feed rate selection based on material hardness and bit diameter.