Chicago-latrobe 47774 Cobalt Jobber Drill Bit No. 40

Product Description

The CHICAGO-LATROBE 47774 is a cobalt jobber-length drill bit sized to wire gauge No. 40 (0.0980 inches decimal) from the Series 550ASP line. It features a 135-degree split point for fast penetration and reduced walking on entry, paired with a straw-colored coating that serves as a heat indicator during high-speed cutting. The right-hand spiral flute geometry evacuates chips efficiently across the 1.375-inch flute length, and the overall length of 2.375 inches keeps the bit compact for controlled drilling. This is a heavy-duty, high-performance bit built for shops and field technicians who need reliable performance in tough materials.

This bit is engineered primarily for drilling stainless steel and hardened materials where standard HSS tooling falls short. The cobalt alloy construction resists heat buildup at elevated cutting speeds, making it well suited for fabrication shops, mechanical contractors, and maintenance technicians working on stainless fastener holes, HVAC equipment panels, and hardened structural components. The tapered web with web-thinning reduces thrust requirements, which is especially useful in hand-held or low-torque drill applications. It meets NAS 907 Type B specification standards.

Key Features

• Wire gauge No. 40 size at 0.0980 inches decimal diameter with a tight tolerance of +0.0000 to -0.0005 inches
• 135-degree split point reduces drill walk and lowers entry thrust on hard surfaces
• Cobalt alloy construction provides heat resistance for cutting stainless steel and hardened materials
• Straw coating acts as a thermal indicator to help monitor cutting temperature
• Tapered web with web-thinning reduces feed force required during drilling
• Meets NAS 907 Type B specification for heavy-duty, high-performance drilling

Compatibility

Designed as a direct-fit replacement or supplemental tooling for any standard straight-shank drill chuck accepting a 0.0980-inch shank diameter. Primary workpiece materials are stainless steel and hardened materials per the Series 550ASP application rating.

Installation Notes

Installation is performed by machinists, fabricators, or trade technicians using any drill press, CNC machine, or hand drill fitted with a compatible straight-shank chuck. Secure the shank fully in the chuck to the depth of the shank length to prevent slippage under load. Use appropriate cutting fluid or lubricant when drilling stainless steel to extend tool life and prevent work hardening. Inspect the split point for wear before use, as a dull point increases heat and can damage the workpiece.