Chicago-latrobe 48911 Screw Machine Drill Bit 11/64 in Lh Hss

Product Description

The CHICAGO-LATROBE 48911 is a screw machine length, left-hand cut drill bit designed for precision hole-making in soft metals, thermoplastics, and wood. Built from high-speed steel (HSS) with a bright uncoated finish, it features a 118-degree standard point angle and a web-thinned, parallel-web configuration for reduced thrust and cleaner entry. The 11/64-inch (0.1719-inch) diameter and compact 2-1/8-inch overall length make it well suited for confined spaces and short-stroke machine spindles. Two regular spiral flutes clear chips efficiently, and the straight shank seats directly in standard drill chucks. This bit is a general-purpose tool intended for machinists, maintenance technicians, and production floor personnel.

The 48911 is suited for screw machine operations, CNC drilling centers, and benchtop drill press work where a shorter flute length reduces deflection and improves hole accuracy. Primary workpiece materials include aluminum, copper, magnesium, slate, thermoplastic, and wood. The left-hand cutting direction is particularly useful when removing broken fasteners or drilling out left-hand-threaded components, as rotational force tends to back out the fastener during the drilling process. The 1-1/16-inch flute length and 1-1/16-inch shank length keep chip evacuation manageable in shallow-depth applications.

Key Features

• Left-hand cut for broken fastener extraction and left-hand threaded applications
• Web-thinned parallel web reduces entry thrust and improves centering
• 118-degree standard point angle works across a broad range of general-purpose materials
• HSS construction with bright uncoated finish suitable for non-ferrous metals, plastics, and wood
• Screw machine length (2-1/8 inches OAL) minimizes deflection in short-stroke setups
• Diameter tolerance of +0.0000 to -0.0007 inches for consistent hole sizing

Compatibility

Designed as an OEM-style general-purpose replacement or production drill bit for screw machine and short-bed drilling applications where a 0.1719-inch left-hand HSS bit with a straight shank is specified. Meets ISO standards for drill bit geometry.

Installation Notes

Installation is performed by machinists or maintenance technicians using a standard drill chuck or collet compatible with a 0.1719-inch straight shank. Secure the workpiece firmly before drilling to prevent spin-out, particularly important with left-hand rotation. Use appropriate cutting fluid or lubricant when drilling copper or aluminum to extend tool life and improve finish quality. Inspect the point for wear before each use; a dull or chipped point will cause oversized holes and excess heat.