Chicago-latrobe 49420 Screw Machine Drill Bit 0.07 in

Product Description

The CHICAGO-LATROBE 49420 is a screw machine length drill bit designed for high-cycle, close-tolerance drilling in metalworking applications. Built from high speed steel (HSS) with a coated finish, this bit handles cast iron and steel with consistent performance across production runs. It measures 0.07 inches (Wire Size 50) in diameter with a 135-degree split point that reduces walking and allows drilling without a center punch. The shortened screw machine length body improves rigidity in turret lathes, drill presses, and CNC screw machines. Web-thinned construction reduces thrust load, extending tool life on heavy-duty jobs.

This drill bit is suited for production machining environments where rigid setups and tight tolerances are required. The Series 159 design is a heavy-duty classification intended for ferrous metals including cast iron and steel. Typical applications include screw machine shops, production drilling operations, and precision fabrication work requiring repeatable hole quality. The straight-cylindrical shank fits standard drill chucks and collet systems commonly found in machine shop equipment.

Key Features

• Wire Size 50 (0.07 inches diameter) with diameter tolerance of +0.0000 to -0.0005 inches for precise hole sizing
• 135-degree split point reduces drill walking and lowers entry thrust on hard ferrous materials
• High speed steel construction with coated finish for improved wear resistance
• Screw machine length body increases rigidity and reduces deflection compared to jobber-length bits
• Web-thinned, parallel web configuration reduces cutting resistance and heat buildup
• Meets NAS 907 and ISO standards for dimensional and performance consistency

Compatibility

Designed as an OEM-style replacement or direct-use screw machine drill bit for production drilling in cast iron and steel workpieces. Compatible with standard drill chucks and collet holders accepting straight-cylindrical shanks in the 0.07-inch diameter range.

Installation Notes

Installation and use should be performed by qualified machinists or tool and die professionals familiar with machine shop practices. Secure the shank fully in the chuck or collet before operation and verify runout is within acceptable limits for the application. Power down and de-energize all equipment before bit changes or chuck adjustments. Do not exceed the recommended feed and speed parameters for the workpiece material, as HSS tooling is susceptible to heat damage from improper feeds.