Chicago-latrobe 50904 Screw Machine Drill Bit 0.073 in Cobalt

Product Description

The CHICAGO-LATROBE 50904 is a screw machine length cobalt drill bit designed for high-performance drilling in ferrous metals including cast iron and steel. At 0.073 inches in diameter (Wire Size 49), it features a 135-degree split point that reduces walking and cutting pressure on entry. The M42 cobalt material grade provides heat resistance and edge retention under heavy-duty drilling conditions. With a total length of 1-11/16 inches and a flute length of 11/16 inch, this stub-length bit delivers rigidity and accurate hole placement in production and repair drilling applications. It is used individually and sold per piece with a minimum order of 12.

This bit is built for trade professionals who drill into cast iron, carbon steel, and alloy steel in production machining, HVAC equipment fabrication, mechanical contracting, and industrial maintenance environments. The screw machine (stub) length format is preferred when rigidity matters more than depth reach, such as when drilling in tight clearances or on drill presses where chatter control is critical. The right-hand spiral flute evacuates chips efficiently, and the web-thinned, parallel-web construction reduces thrust requirements on the workpiece.

Key Features

• M42 cobalt construction for heat resistance and extended tool life in ferrous metals
• 135-degree split point reduces bit walking and lowers entry thrust force
• Web-thinned parallel web design decreases drilling resistance
• Screw machine (stub) length provides increased rigidity versus jobber-length bits
• Straight-cylindrical shank fits standard three-jaw drill chucks
• Diameter tolerance of +0.0000 to -0.0005 inches for consistent hole sizing
• Meets ISO standards; Series 559 heavy-duty classification

Compatibility

Designed as an OEM-style replacement and production-use bit for applications requiring a Wire Size 49 (0.0730 inch) screw machine length drill bit compatible with standard straight-shank drill chucks. Primary workpiece materials are cast iron and steel.

Installation Notes

Installation is performed by machinists, tool-and-die technicians, mechanical contractors, and HVAC fabrication professionals. Secure the straight-cylindrical shank firmly in a properly sized drill chuck before operation, and ensure the chuck key is removed before starting the spindle. When drilling cast iron or hardened steel, use appropriate cutting fluid or coolant where the machine setup allows, and reduce feed pressure to avoid overloading the small-diameter cutting edge. Inspect the bit for chipping or wear before each use, as small-diameter cobalt bits can fracture without visible warning if run at incorrect speeds or feeds.