Chicago-latrobe 50813 Screw Machine Drill Bit 1/4 in Cobalt

Product Description

The CHICAGO-LATROBE 50813 is a cobalt screw machine length drill bit engineered for heavy-duty drilling in ferrous materials. Built from M42 cobalt steel, this bit handles the heat and wear demands of production drilling in cast iron and steel without breaking down prematurely. The 135-degree split point self-centers on contact, reducing walking and the need for a center punch. At 0.25 inches (1/4 inch, Letter E) in diameter with a 2-tooth spiral flute design, it delivers efficient chip evacuation and consistent hole quality. This bit is sized and constructed for shop environments where reliability across repeated use cycles is non-negotiable.

The 50813 is suited for machining, fabrication, and maintenance applications where screw machine length bits are preferred for rigidity over jobber-length alternatives. Its shorter body reduces deflection during drilling in tight spaces or on CNC drill presses, manual drill presses, and screw machines. Primary target materials are cast iron and steel. The straight-cylindrical shank seats cleanly in standard chucks. This bit is a direct fit for any operation running 1/4-inch diameter holes in ferrous stock that demands a heavy-duty cobalt grade.

Key Features

• M42 cobalt construction resists heat buildup during high-speed drilling in steel and cast iron
• 135-degree split point reduces thrust, eliminates walking, and improves hole entry accuracy
• Web-thinned parallel web for lower cutting resistance and better chip clearance
• Screw machine (stub) length improves rigidity and reduces deflection versus jobber-length bits
• Right-hand cut, regular spiral flute with straight-cylindrical shank for universal chuck compatibility
• Diameter tolerance of +0.0000 to -0.0007 inches for consistent, repeatable hole sizing

Compatibility

Designed as a heavy-duty OEM-style replacement or service bit for use with standard drill presses, screw machines, and CNC equipment accepting straight-cylindrical shank bits in 1/4-inch diameter; conforms to ISO standards as listed in Series 559.

Installation Notes

A licensed machinist or qualified technician should secure the straight-cylindrical shank firmly in the chuck before operation, verifying runout before beginning the drilling cycle. Always power down and lock out the machine before changing bits. Use appropriate cutting fluid or coolant when drilling steel to extend bit life, even though this bit does not support coolant-through delivery. Wear appropriate PPE including eye protection when operating rotary cutting tools.