Chicago-latrobe 49220 5/16 in Screw Machine Drill Bit Hss

Product Description

The CHICAGO-LATROBE 49220 is a screw machine length drill bit designed for high-production drilling in cast iron and steel. Built from heavy-duty high speed steel with a protective coating, it features a 135-degree split point that reduces walking and cutting pressure on entry. The web-thinned, parallel web construction improves chip evacuation and lowers thrust load. At 2-13/16 inches overall length with a 1-5/8-inch flute, this stub-length geometry provides added rigidity compared to jobber-length bits, making it well suited to CNC machining centers, drill presses, and screw machine operations where chatter and deflection must be minimized.

The 49220 is intended for metalworking applications in industrial and maintenance environments. Primary workpiece materials are cast iron and steel. The straight-cylindrical shank accepts standard drill chucks without an adapter. The screw machine (stub) length is the preferred choice when drilling through fixtures, jigs, or thin stock where a shorter bit reduces vibration and improves hole accuracy. It conforms to NAS 907 and ISO standards, making it suitable for aerospace and precision manufacturing workflows.

Key Features

• 135-degree split point reduces thrust and eliminates center-punch requirement on most metals
• Web-thinned parallel web lowers cutting resistance and promotes chip clearing
• Heavy-duty high speed steel construction rated for cast iron and steel
• Screw machine (stub) length adds rigidity and reduces deflection versus jobber-length bits
• Right-hand spiral flute with regular helix for consistent chip evacuation
• Meets NAS 907 and ISO specifications for precision and aerospace applications

Compatibility

Designed as a heavy-duty OEM-style replacement or production drill bit for metalworking operations involving cast iron and steel workpieces. Conforms to NAS 907 and ISO standards.

Installation Notes

Installation should be performed by a qualified machinist or maintenance technician. Secure the straight-cylindrical shank fully into a properly sized drill chuck before operation, and verify chuck runout is within acceptable limits to protect the tight diameter tolerance of +0.0000 to -0.0010 inches. Always power down and lock out the machine before changing bits. Use appropriate cutting fluid or coolant as required by the base material to extend tool life.