Chicago-latrobe 49378 Screw Machine Drill Bit 0.199 in

Product Description

The CHICAGO-LATROBE 49378 is a screw machine length drill bit designed for high-production drilling in cast iron and steel. Built from high speed steel with a coated finish, this bit features a 135-degree split point and a web-thinned, parallel web construction that reduces thrust and improves hole entry. The straight-cylindrical shank seats securely in standard drill chucks. At 2.25 inches overall length with a 1.1875-inch flute length, the short body resists deflection in tight clearance applications. This is a heavy-duty Series 159 bit intended for machinists, maintenance professionals, and fabricators working in metal-cutting environments.

Screw machine length bits are a standard choice for CNC drilling, turret lathes, and drill presses where rigidity and accuracy matter more than reach. The 49378 is sized at 0.1990 inches diameter (Wire Size 8), placing it within the 0.1500 to 0.2000 inch range suited for close-tolerance fastener pilot holes and tapped hole preparation in steel and cast iron workpieces. The right-hand spiral flute evacuates chips efficiently in these materials. This bit is sold individually per package and is available in multiples of 12.

Key Features

• 135-degree split point reduces walking and lowers required feed force on entry
• Web-thinned parallel web construction decreases cutting resistance in hard metals
• High speed steel construction with coated finish for extended wear life
• Screw machine length body minimizes deflection in close-clearance and high-speed setups
• Right-hand spiral flute promotes efficient chip evacuation in steel and cast iron
• Meets NAS 907 specification designation for dimensional and performance consistency

Compatibility

Designed as an OEM-style replacement or direct-use drill bit for standard drill chucks and collets accepting straight-cylindrical shanks in screw machine, CNC, and manual drill press applications targeting cast iron and steel workpieces.

Installation Notes

Installation is performed by qualified machinists or maintenance technicians familiar with metal-cutting operations. Secure the straight-cylindrical shank firmly in a compatible chuck or collet before operation, and verify runout is within acceptable limits for the tolerance class required. Always follow machine manufacturer guidelines for spindle speed and feed rate when drilling cast iron or steel. Wear appropriate PPE including eye protection whenever drilling metal.