Chicago-latrobe 48505 5/64 Inch Screw Machine Drill Bit Hss

Product Description

The CHICAGO-LATROBE 48505 is a screw machine length drill bit designed for general-purpose drilling in cast iron, non-ferrous metals, and steel. The bit measures 5/64 inch (0.0781 inches) in diameter with an overall length of 1-11/16 inches and a flute length of 11/16 inches. The shorter body length of screw machine bits provides added rigidity compared to jobber-length bits, reducing deflection in tight or confined drilling applications. Constructed from high speed steel with a bright/uncoated finish, the 48505 features a standard 118-degree point angle and a web-thinned parallel web configuration for easier penetration and reduced thrust. Machinists, maintenance technicians, and metalworking tradespeople install this bit in hand drills, drill presses, and screw machines.

This drill bit is suited for production and maintenance drilling in metal fabrication, general machining, and light industrial environments. The 5/64-inch diameter is a common size for pilot holes, through-holes in sheet metal, and pre-drill passes before tapping. Its straight-cylindrical shank accepts standard drill chucks. The Series 157 designation identifies this as a current Chicago-Latrobe production line bit, built to ISO standards for consistent dimensional accuracy across the cutting diameter tolerance of +0.0000 to -0.0005 inches.

Key Features

• 5/64 inch diameter (0.0781 inches) with tight tolerance: +0.0000 to -0.0005 inches
• 118-degree standard point angle for general-purpose metal drilling
• Web-thinned parallel web reduces cutting thrust and entry resistance
• High speed steel construction handles cast iron, non-ferrous metals, and steel
• Screw machine length body (1-11/16 inches overall) improves rigidity and reduces deflection
• Bright/uncoated finish — no coating to flake or chip under heat cycling
• Built to ISO dimensional standards, Series 157

Compatibility

Designed as a general-purpose replacement or production drill bit compatible with any standard drill chuck accepting a straight-cylindrical shank. Rated for primary workpiece materials including cast iron, non-ferrous metal, and steel.

Installation Notes

Install and remove this bit with the drill or drill press powered down and the chuck fully released. Use appropriate cutting fluid or lubricant when drilling steel to extend bit life and reduce heat buildup. Ensure the chuck jaws seat squarely on the straight-cylindrical shank before tightening to prevent runout. Inspect the cutting edges for wear or chipping before each use, particularly in production drilling cycles.