Chicago-latrobe 48401 Screw Machine Drill Bit Hss 31

Product Description

The CHICAGO-LATROBE 48401 is a screw machine length drill bit engineered for heavy-duty drilling applications in cast iron and steel. It measures 0.12 inches (wire size 31) in diameter with an overall length of 1-7/8 inches and a flute length of 7/8 inch. The 135-degree split point reduces walking and cutting force at entry, and the web-thinned, parallel-web construction improves chip clearance. Manufactured from high speed steel with a coated finish, this bit delivers consistent performance in production and maintenance drilling environments. It is sized to the Series 2159 specification and carries NAS 907 designation for dimensional compliance.

This drill bit is suited for machinists, pipefitters, ironworkers, and general maintenance technicians working with cast iron and steel in both shop and field settings. The screw machine length body, shorter than a jobber bit, provides added rigidity in drill press, turret lathe, and CNC applications where stub reach is preferred. The 2-flute spiral configuration handles standard through-hole and blind-hole work at typical production feed rates. The straight cylindrical shank seats directly into standard chucks without adapters.

Key Features

• 135-degree split point reduces drill walk and lowers entry force on hard metals
• Web-thinned parallel web improves chip evacuation and reduces thrust load
• Screw machine length body provides greater rigidity than jobber-length equivalents
• High speed steel construction with coated finish for extended wear resistance
• Right-hand cut, 2-flute spiral design handles cast iron and steel
• Diameter tolerance of plus 0.0000 to minus 0.0005 inches for consistent hole sizing
• Meets NAS 907 and ISO standards for dimensional accuracy

Compatibility

Designed as a Series 2159 screw machine length drill bit suitable for use in cast iron and steel with primary workpiece materials falling within the 0.1000 to 0.1500 inch decimal inch drill bit size range.

Installation Notes

This bit is installed and operated by machinists and trade technicians using standard 3-jaw drill chucks or collet-style tool holders. Secure the straight cylindrical shank fully in the chuck before operation to prevent runout. Use appropriate cutting fluid or coolant for extended drilling cycles in ferrous materials, noting that this bit does not support coolant-through operation. Inspect the cutting edges for wear before each use and replace the bit when point geometry degrades to avoid oversized holes or workpiece damage.