Chicago-latrobe 48221 Screw Machine Drill Bit 21/64 in Hss

Product Description

The CHICAGO-LATROBE 48221 is a screw machine length drill bit designed for high-production drilling in cast iron and steel. Built from high speed steel (HSS) with a coated finish, this bit features a 135-degree split point for fast penetration and reduced walking on entry. The stub-length body keeps the drill rigid under load, making it well suited for drill press and CNC lathe work where shorter overhang reduces deflection. With a diameter of 0.3281 inches (21/64 inch) and an overall length of 2-15/16 inches, it fits standard chucks and quick-change systems in production environments. A parallel web configuration and web-thinned geometry support clean chip evacuation in tough ferrous materials.

This bit is intended for metalworking applications in manufacturing, maintenance, and fabrication shops. Typical use cases include drilling operations on cast iron components, structural steel, and machined steel parts in both manual and CNC setups. The heavy-duty tool performance rating and NAS 907 specification make it appropriate for aerospace-grade and industrial metalworking environments where dimensional accuracy and consistent hole quality are required. The straight-cylindrical shank is compatible with standard drill chucks across most benchtop and floor-standing drill presses and lathes.

Key Features

• 21/64 inch (0.3281 inches) diameter with tight tolerance of +0.0000 to -0.0010 inches for precise hole sizing
• 135-degree split point reduces thrust force and eliminates the need for a center punch on most metals
• Web-thinned, parallel web design promotes efficient chip evacuation in cast iron and steel
• High speed steel construction with coated finish extends tool life in abrasive ferrous materials
• Screw machine (stub) length of 2-15/16 inches overall provides rigidity and minimizes deflection
• Meets NAS 907 and ISO standards for dimensional and performance consistency

Compatibility

Designed for drilling cast iron and steel workpieces. The straight-cylindrical shank fits standard drill chucks used in drill presses, engine lathes, and CNC turrets. Compatible with primary workpiece materials listed as cast iron and steel per Series 2159 specifications.

Installation Notes

Installation and use should be performed by a qualified machinist or metalworking technician familiar with cutting tool setup. Secure the workpiece and verify spindle speed is appropriate for the material and diameter before starting. Ensure the drill chuck is fully tightened and the shank is seated cleanly before applying feed pressure. Do not run the bit without adequate chip clearance, and use cutting fluid or coolant appropriate for the workpiece material to maintain tool life.