Chicago-latrobe 50639 Extra Length Drill Bit 11/16 in Hss

Product Description

The CHICAGO-LATROBE 50639 is an extra length high speed steel drill bit engineered for deep-hole and long-reach drilling applications. It measures 11/16 inch (0.6875 inches) in diameter with a 12-inch overall length and a 9-inch spiral flute length, providing extended reach into workpieces where standard-length bits cannot access. The 118-degree notched drill point and web-thinned, tapered web construction reduce entry force and improve chip evacuation. An oxide finish adds surface hardness and basic corrosion resistance. This bit is suited for professional machinists, maintenance technicians, and fabricators working with cast iron and steel.

The 50639 is designed for long-reach drilling in cast iron and steel workpieces, covering applications such as deep blind holes, cross-drilling through structural members, and extended-reach work in fabrication and maintenance environments. The straight-cylindrical shank at 0.6875 inches diameter fits standard three-jaw drill chucks on drill presses, CNC machining centers, and heavy-duty hand drills. Right-hand cutting direction is standard. The Series 120X designation places it in a line of general-purpose extra-length bits intended for production and job-shop use.

Key Features

• 11/16 inch (0.6875 inches) diameter with diameter tolerance of +0.0000 to -0.0012 inches for consistent fit
• 12-inch overall length and 9-inch flute length for extended long-reach drilling
• 118-degree notched point with web thinning reduces thrust and improves center starting
• High speed steel construction with oxide finish for use in cast iron and steel
• Straight-cylindrical shank fits standard drill chucks without adapters
• Regular spiral, 2-flute design promotes chip clearance in deep-hole applications

Compatibility

Designed for use in cast iron and steel workpieces. The 0.6875-inch straight-cylindrical shank is compatible with standard three-jaw drill chucks accepting up to 11/16 inch shank diameter on drill presses, machining centers, and heavy-duty portable drills.

Installation Notes

Secure the shank fully in the drill chuck and verify runout before drilling. Use appropriate cutting fluid or coolant for steel applications to extend tool life and prevent work hardening. Ensure the workpiece is firmly clamped before engaging the bit, particularly at extended reach. Comply with applicable shop safety standards and machine manufacturer guidelines when operating at depth.