Chicago-latrobe 70231 Jobber Drill Bit 31/64 in Hss Tin

Product Description

The CHICAGO-LATROBE 70231 is a jobber-length twist drill bit designed for general-purpose drilling in steel and cast iron. It is manufactured from high speed steel and coated with titanium nitride (TiN) to extend tool life and reduce friction during cutting. The bit measures 31/64 inches in diameter with a 118-degree standard point angle and a web-thinned tip for easier penetration and reduced thrust. Overall length is 5-7/8 inches with a 4-3/8-inch spiral flute. The straight-cylindrical shank seats securely in standard drill chucks. This bit is part of the Series 150T and conforms to DIN 338 standards.

The 70231 is suited for production and maintenance drilling applications in metalworking environments, fabrication shops, and field service settings. Its regular spiral flute and right-hand cut make it a straightforward choice for through-holes and blind holes in ferrous metals. Machinists, pipefitters, ironworkers, and maintenance technicians working with steel structural components and cast iron fixtures will find this bit appropriate for everyday drilling tasks.

Key Features

• 31/64-inch diameter with diameter tolerance of -0.0010 to 0.0000 inches for consistent hole sizing
• Titanium nitride (TiN) coating improves surface hardness and reduces heat buildup during cutting
• 118-degree standard point angle with web-thinned, tapered web for reduced entry thrust
• High speed steel construction suitable for ferrous metals including steel and cast iron
• Regular right-hand spiral flute with 4-3/8-inch flute length for efficient chip evacuation
• Conforms to DIN 338 standard; Series 150T general-purpose grade

Compatibility

Designed as a general-purpose jobber-length drill bit compatible with standard drill chucks accepting a straight-cylindrical shank. Primary workpiece materials are steel and cast iron as specified by the manufacturer.

Installation Notes

Installation is performed by machinists, maintenance technicians, or trade professionals using a drill press, hand drill, or mill with a compatible chuck. Secure the straight-cylindrical shank fully in the chuck before operation and confirm the chuck is tightened appropriately. Use cutting fluid or a suitable coolant when drilling steel or cast iron at sustained feed rates to preserve coating life, noting this bit does not support coolant-through delivery. Inspect the cutting edge for wear or chipping before each use and replace the bit if the TiN coating is worn through at the tip.