Chicago-latrobe 49379 Screw Machine Drill Bit 0.196 in Hss

Product Description

The CHICAGO-LATROBE 49379 is a screw machine length drill bit designed for high-productivity drilling in cast iron and steel. It measures 0.196 inches in diameter (Wire Size 9) with a 135-degree split point that reduces walking and requires less feed force than a standard 118-degree geometry. The bit is manufactured from high speed steel with a coated finish for improved wear resistance. At 2.25 inches overall length and a 1.1875-inch flute length, the stub-length body provides added rigidity and reduced deflection compared to jobber-length bits. Licensed machinists, tool and die technicians, and industrial maintenance mechanics are the primary installers and users.

This bit is suited for screw machine operations, CNC drilling, and manual drill press work where short-length rigidity is required. The parallel web configuration with web thinning reduces thrust requirements, making it effective in production environments handling cast iron and steel workpieces. The right-hand spiral flute evacuates chips efficiently in these materials. Series 159 is Chicago-Latrobe's heavy-duty screw machine line, built to NAS 907 specification and meeting ISO standards. Typical applications include repetitive-hole production drilling and close-tolerance work where diameter control matters.

Key Features

• 135-degree split point reduces bit walking and lowers required feed pressure
• Web-thinned parallel web reduces drilling thrust in cast iron and steel
• Stub screw machine length (2.25 inches overall) increases rigidity and reduces deflection
• High speed steel construction with coated finish for extended tool life
• Diameter tolerance of +0.0000 to -0.0007 inches for close-tolerance hole sizing
• Meets NAS 907 specification and ISO standards

Compatibility

Designed for drilling cast iron and steel workpieces. Compatible with standard straight-shank drill chucks on drill presses, screw machines, and CNC machining centers. Diameter falls within the 0.1500 to 0.2000 inch range of the Series 159 screw machine line.

Installation Notes

Install into a compatible straight-shank drill chuck and verify chuck runout before use. Secure the workpiece firmly before drilling to prevent movement. Use appropriate cutting fluid or coolant on the workpiece surface when drilling steel to manage heat buildup. Inspect the cutting edges and split point for wear or chipping before each use and replace when edge condition degrades.