Chicago-latrobe 49392 Screw Machine Drill Bit 0.157 in Hss

Product Description

The CHICAGO-LATROBE 49392 is a screw machine length drill bit designed for high-production drilling in cast iron and steel. Built from heavy-duty high speed steel with a coated finish, it offers a 135-degree split point that reduces walking and cutting force on entry. The web-thinned, parallel-web construction supports consistent chip evacuation through its two spiral flutes. At 0.157 inches (wire size #22) in diameter, this bit fits screw machine and short-hole drilling applications where rigidity and precision matter. Licensed machinists, tool-and-die shops, and trade mechanics installing equipment fasteners are the primary users.

This drill bit is suited for production drilling in ferrous metals, specifically cast iron and steel, in both shop and field maintenance settings. The screw machine length format — shorter overall length than a jobber bit — provides added rigidity and reduced deflection in drill press, turret lathe, and CNC screw machine setups. The straight-cylindrical shank seats directly in standard drill chucks without adapters. It meets NAS 907 and ISO standards, making it appropriate for aerospace-adjacent and precision manufacturing environments.

Key Features

• 135-degree split point reduces thrust and prevents bit walking on entry
• Web-thinned, parallel-web design supports efficient chip removal
• Heavy-duty high speed steel construction rated for cast iron and steel
• Screw machine length (2.125 inches overall) provides superior rigidity over jobber-length bits
• Diameter tolerance held to +0.0000 to -0.0007 inches for precise hole sizing
• Meets NAS 907 and ISO standards for precision and aerospace-adjacent applications

Compatibility

Designed as an OEM-style replacement or direct substitute for screw machine length drill bits in Series 159 applications targeting cast iron and steel workpieces.

Installation Notes

Install in a standard drill chuck sized for a straight-cylindrical shank before powering the machine. Machinists and maintenance mechanics should ensure the chuck is fully tightened and the workpiece is secured before operation. Always follow applicable shop safety standards and machine manufacturer guidelines when selecting feeds and speeds for high speed steel tooling in ferrous materials.