Chicago-latrobe 48807 Screw Machine Drill Bit 0.261 in Hss

Product Description

The CHICAGO-LATROBE 48807 is a screw machine length drill bit designed for fast, accurate drilling in production and general-purpose machining environments. Built from high speed steel (HSS) with a bright/uncoated finish, it measures 0.261 inches in diameter and carries a 118-degree standard point angle. At an overall length of 2-5/8 inches and a flute length of 1-7/16 inches, this stub-length format delivers added rigidity compared to jobber-length bits, reducing deflection during entry. The parallel web and web-thinned geometry improve chip clearance and reduce thrust force at the point. Two spiral flutes with a regular spiral pattern handle chip evacuation efficiently across a range of materials.

This Series 157 bit is suited for screw machine operations, CNC drilling centers, drill presses, and manual machining setups where a shorter, stiffer bit is preferred. Primary workpiece materials include cast iron, non-ferrous metals, and steel, making it a solid choice for production shops, maintenance machinists, and fabricators. The straight-cylindrical shank seats in standard drill chucks without modification, and the right-hand cut direction is compatible with conventional spindle rotation on all standard machine tools.

Key Features

• 0.261 inch (Letter G) diameter with a tight tolerance of +0.0000 to -0.0010 inches for precise hole sizing
• 118-degree standard point angle with web-thinned, parallel web geometry for reduced thrust and cleaner starts
• High speed steel construction provides durability across cast iron, steel, and non-ferrous metal workpieces
• Screw machine (stub) length at 2-5/8 inches overall adds rigidity and reduces deflection versus jobber-length bits
• Bright/uncoated finish — compatible with cutting fluids and suitable for regrinding
• Right-hand cut, two-flute spiral design for efficient chip removal in through-hole and blind-hole drilling

Compatibility

Designed as a general-purpose screw machine length drill bit suitable for use in standard drill chucks accepting straight-cylindrical shanks across drill presses, CNC machining centers, and screw machine setups. Meets ISO standards for tooling dimensions.

Installation Notes

Secure the straight-cylindrical shank firmly in a drill chuck or collet before operation, and verify that the chuck is fully tightened and the spindle is locked before making any adjustments. Always bring the spindle to a complete stop before changing bits or clearing chips. Apply cutting fluid appropriate to the workpiece material to extend tool life and improve hole finish. Inspect the cutting edges before each use and replace or regrind the bit at the first sign of chipping or dulling.