Chicago-latrobe 49405 Screw Machine Drill Bit 7/64 Hss

Product Description

The CHICAGO-LATROBE 49405 is a screw machine length drill bit designed for heavy-duty drilling in cast iron and steel. Built from high speed steel with a coated finish, it carries a 135-degree split point that reduces walking and cutting force at entry. The parallel web construction and web-thinned tip improve chip clearance and reduce thrust in production drilling environments. At 1-7/8 inches overall length with a 7/8-inch flute length, this stub-length geometry delivers increased rigidity over jobber-length bits. It is sized at 7/64 inch (0.1100 inch decimal, Wire Size 35) with a diameter tolerance of +0.0000 to -0.0005 inches, making it suitable for close-tolerance work. Machinists, maintenance technicians, and tool-room professionals use this bit for repetitive, high-volume drilling operations.

The 49405 is suited for drilling cast iron and steel in both production and maintenance applications. Its screw machine length reduces deflection in short-reach drilling setups, making it a practical choice for drill press work, CNC operations, and hand-held power tools where a compact bit with high rigidity is required. The straight-cylindrical shank fits standard drill chucks without modification. The two-flute spiral design promotes efficient chip evacuation in ferrous materials.

Key Features

• 135-degree split point reduces thrust and prevents bit walking on entry
• Web-thinned, parallel web construction improves chip clearance and reduces cutting force
• Screw machine (stub) length at 1-7/8 inches overall provides superior rigidity over jobber-length bits
• High speed steel construction with coated finish extends service life in ferrous materials
• Diameter tolerance of +0.0000 to -0.0005 inches supports close-tolerance hole requirements
• Meets NAS 907 specification and ISO standards for dimensional and performance consistency

Compatibility

Designed as a heavy-duty screw machine length drill bit for use in cast iron and steel workpieces. Primary workpiece materials listed by the manufacturer are cast iron and steel.

Installation Notes

Install in a standard drill chuck sized for straight-cylindrical shanks. Secure the workpiece before drilling to prevent movement. Use appropriate cutting fluid or coolant when drilling ferrous materials to manage heat buildup, noting this bit does not support internal coolant-through delivery. Follow applicable shop safety practices and machine guarding requirements when operating drill presses or powered hand tools.