Chicago-latrobe 48915 Screw Machine Drill Bit 15/64 Hss

Product Description

The CHICAGO-LATROBE 48915 is a screw machine length drill bit designed for general-purpose drilling in a wide range of materials. Built from high-speed steel (HSS) with a bright, uncoated finish, this bit features a 15/64 inch (0.2344 inch) diameter, a 118-degree drill point angle, and a left-hand cutting direction. The screw machine length format provides a shorter, more rigid profile than jobber-length bits, reducing deflection in drilling applications that demand tight tolerances. It carries a diameter tolerance of +0.0000 to -0.0007 inches, making it suitable for precision work. This bit is installed and used by machinists, tool and die technicians, and trade professionals working with drill presses, CNC equipment, or hand-held power tools.

The 48915 is suited for drilling aluminum, copper, magnesium, slate, thermoplastic, and wood. Its screw machine length makes it a practical choice for production drilling, fixture work, and applications where stub-length rigidity is preferred over the extended reach of standard jobber bits. The left-hand cutting direction is particularly useful when extracting broken fasteners or drilling alongside left-hand threaded components, as the bit tends to back out the workpiece rather than drive it further in. It is appropriate for both shop and field use across light manufacturing, HVAC fabrication, plumbing rough-in, and electrical work where non-ferrous materials are common.

Key Features

• Left-hand cut direction aids in broken fastener extraction and left-hand threaded applications
• Screw machine length profile provides added rigidity and reduced deflection versus jobber-length bits
• 118-degree standard point angle suits general-purpose drilling across non-ferrous metals and soft materials
• Web-thinned parallel web construction improves chip clearance and reduces thrust during entry
• Bright, uncoated HSS finish compatible with a wide range of cutting fluids and dry drilling
• Diameter tolerance of +0.0000 to -0.0007 inches supports consistent hole sizing

Compatibility

Designed as a general-purpose left-hand screw machine drill bit in the Chicago-Latrobe Series 157L, suitable for use in standard straight-shank drill chucks on drill presses, CNC drilling machines, and hand-held power drills. Primary workpiece materials include aluminum, copper, magnesium, slate, thermoplastic, and wood.

Installation Notes

Installation and use of this drill bit should follow standard machine shop safety practices, including securing workpieces firmly before drilling and wearing appropriate eye protection. Ensure the drill chuck is properly tightened and the shank is fully seated before operation. Left-hand bits rotate opposite to standard bits, so confirm your drill or machine is set to reverse before use. Disengage power and allow the spindle to come to a complete stop before changing bits or adjusting the workpiece.