Chicago-latrobe 50853 Screw Machine Drill Bit 0.397 in

Product Description

The CHICAGO-LATROBE 50853 is a cobalt screw machine length drill bit sized at 0.397 inches (Letter X) and designed for heavy-duty metal cutting in demanding shop and field applications. Built from M42 cobalt high-speed steel, it features a 135-degree split point that reduces walking and lowers thrust on entry, making it well suited for hard and abrasive workpiece materials. The two-flute spiral design with web-thinned, parallel-web construction promotes chip evacuation and reduces heat buildup during extended drilling cycles. Licensed trades and machining professionals use this bit where standard HSS tooling wears prematurely.

The 50853 is intended for drilling cast iron and steel in production and maintenance environments. Its screw machine length profile — 3-5/16 inches overall with a 1-15/16-inch flute length — provides a compact, rigid setup that reduces deflection in drill press, CNC, and hand-drill applications. The straight-cylindrical shank seats securely in standard three-jaw chucks and keyed drill chucks without the need for adapters. Right-hand cutting direction is standard for conventional drilling operations.

Key Features

• M42 cobalt construction for extended tool life in hard and abrasive metals
• 135-degree split point reduces thrust and minimizes bit walking on entry
• Web-thinned parallel web lowers cutting resistance and improves chip clearance
• Screw machine length body provides added rigidity over jobber-length equivalents
• Right-hand spiral flute with coated finish for reduced friction during drilling
• ISO standard construction with tight diameter tolerance of plus 0.0000 to minus 0.0010 inches

Compatibility

Designed as a heavy-duty OEM-style replacement or direct-use drill bit for applications in cast iron and steel; compatible with any standard three-jaw or keyed chuck accepting a straight-cylindrical shank at the 0.397-inch diameter range within the Series 559 product line.

Installation Notes

This bit is intended for use by machinists, millwrights, and maintenance technicians operating drill presses, lathes, or hand-held power drills. Secure the straight-cylindrical shank firmly in a properly sized chuck before operation and verify chuck key is removed before powering on equipment. Use cutting fluid or coolant appropriate to the workpiece material to extend tool life, particularly when drilling steel. Inspect the cutting edges and web before each use and replace if chipping or heat discoloration is observed.