Chicago-latrobe 70139 Jobber Drill Bit Wire 39 Hss Tin

Product Description

The CHICAGO-LATROBE 70139 is a jobber-length drill bit in wire gauge size 39, equivalent to 0.0995 inches in decimal diameter. Built from high speed steel with a titanium nitride (TiN) coating, it delivers improved surface hardness and extended cutting life compared to uncoated HSS. The 118-degree standard point angle suits general-purpose drilling across a wide range of materials. With an overall length of 2.375 inches and a flute length of 1.375 inches, the 70139 fits standard drill chucks and is at home in production shops, maintenance operations, and fabrication environments where wire-gauge bits are a daily tool.

This bit is suited for drilling cast iron and steel in both light production and general maintenance applications. The straight-cylindrical shank at 0.0995 inches in diameter seats reliably in keyed or keyless chucks. The regular spiral flute geometry promotes efficient chip evacuation during through-hole drilling. It follows DIN 338 dimensional standards, making it a familiar spec for shops sourcing to metric-compatible tooling programs. Machinists, toolmakers, and maintenance technicians working with ferrous materials will find the 70139 a dependable everyday option.

Key Features

• Wire gauge size 39 (0.0995 inches) with a diameter tolerance of -0.0005 to 0.0000 inches for consistent hole sizing
• High speed steel construction with titanium nitride coating for increased surface hardness and wear resistance
• 118-degree standard point angle for general-purpose entry into cast iron and steel
• 2-flute regular spiral geometry with web-thinned, tapered web for reduced thrust and cleaner chip flow
• Straight-cylindrical shank at 1.0 inch shank length seats securely in standard drill chucks
• DIN 338 compliant jobber-length series 150T design

Compatibility

Designed as a general-purpose jobber-length drill bit for use in standard drill chucks accepting a 0.0995-inch straight-cylindrical shank. Primary workpiece materials are cast iron and steel.

Installation Notes

Install in a drill press, CNC machining center, or hand drill with a chuck rated for the shank diameter. Secure the shank fully in the chuck before starting the spindle. Use appropriate cutting fluid or coolant for ferrous materials to manage heat buildup, especially at higher spindle speeds. Inspect the cutting edges before each use and replace the bit if chipping or excessive wear is observed.