Chicago-latrobe 48720 Screw Machine Drill Bit 0.161 in Hss

Product Description

The CHICAGO-LATROBE 48720 is a screw machine length drill bit designed for general-purpose drilling in metal fabrication and machining applications. Built from high speed steel with a bright, uncoated finish, this bit features a 0.161 inch diameter corresponding to wire size 20 and a standard 118-degree split point angle. The shorter screw machine length body provides added rigidity compared to jobber-length bits, reducing deflection in production drilling setups. The 2-flute spiral design with web thinning improves chip evacuation and reduces feed force at the cutting point. Licensed machinists, tool-and-die technicians, and metalworking trades install this bit for close-tolerance work in cast iron, non-ferrous metals, and steel.

This drill bit fits standard production drilling environments where rigidity and dimensional accuracy matter. The straight cylindrical shank seats in conventional three-jaw drill chucks on drill presses, CNC turret machines, and screw machines. The 0.161 inch diameter holds a tolerance of +0.0000 to -0.0007 inches, making it appropriate for hole preparation in close-tolerance assemblies. Primary workpiece materials include cast iron, non-ferrous metal, and steel. The Series 157 designation identifies it within the CHICAGO-LATROBE general-purpose high speed steel drill line built to ISO standards.

Key Features

• 0.161 inch diameter, wire size 20, with a tight tolerance of +0.0000 to -0.0007 inches
• High speed steel construction rated for cast iron, non-ferrous metals, and steel
• 118-degree standard point angle with web thinning for reduced thrust and easier starting
• Screw machine length body increases rigidity and minimizes bit deflection
• Bright, uncoated finish suitable for general-purpose use without coating wear concerns
• 2-flute regular spiral design promotes efficient chip clearance during drilling

Compatibility

Designed as an OEM-style general-purpose drill bit compatible with standard straight-shank drill chucks used on drill presses, screw machines, and CNC turret equipment drilling cast iron, non-ferrous metal, and steel workpieces.

Installation Notes

Machinists and metalworking technicians should secure the straight cylindrical shank fully in a properly sized drill chuck before operation. Ensure the workpiece is clamped or fixtured to prevent rotation during drilling. Use appropriate cutting fluid for steel and cast iron applications to extend bit life and maintain hole tolerance. Inspect the cutting edges for wear or chipping before each use, as a degraded point will cause oversize holes and increased thrust.