Chicago-latrobe 48549 Screw Machine Drill Bit 49/64 in Hss

Product Description

The CHICAGO-LATROBE 48549 is a screw machine length drill bit designed for high-production drilling in metalworking applications. Built from high speed steel with a coated finish, this bit delivers consistent performance cutting through cast iron, non-ferrous metals, and steel. The 49/64 inch (0.7656 inch) diameter, 118-degree standard point angle, and web-thinned geometry help reduce thrust and improve chip clearance. The parallel web configuration and regular spiral flute promote efficient material evacuation. At 5.125 inches overall length, this stub-length format provides added rigidity compared to jobber-length bits, making it well suited for drill press and CNC turret work.

This bit is a general purpose tool used in machine shops, fabrication facilities, and maintenance environments. The screw machine length format is commonly specified when drilling in materials such as structural steel, aluminum, copper, and gray cast iron where shorter overhang reduces deflection and chatter. It installs in drill presses, screw machines, CNC machining centers, and manual turret lathes equipped with a straight-shank chuck or collet sized for the 49/64 inch diameter shank. No coolant-through capability is required for general purpose applications, though flood coolant or cutting fluid is recommended when drilling deeper holes or harder alloys.

Key Features

• 49/64 inch (0.7656 inch) diameter with a tight tolerance of +0.0000 to -0.0012 inches
• High speed steel construction with a coated finish for extended tool life
• 118-degree standard point angle with web-thinned, parallel web for reduced entry thrust
• Regular spiral flute with 2 flutes for reliable chip evacuation in ferrous and non-ferrous materials
• Screw machine (stub) length at 5.125 inches overall and 3.25 inches flute length for increased rigidity
• Right-hand cut, straight-cylindrical shank compatible with standard drill chucks and collets
• Series 157 general purpose grade, manufactured to ISO standards

Compatibility

Designed for use on cast iron, non-ferrous metals, and steel workpieces. Compatible with any drill press, CNC turret, screw machine, or machining center equipped with a chuck or collet that accepts a straight-cylindrical shank at 49/64 inch diameter.

Installation Notes

Secure the shank fully in a properly sized chuck or collet before beginning any drilling operation. Always power down and lock out the spindle before changing bits. Use cutting fluid or flood coolant to extend tool life and manage heat when drilling harder alloys or at elevated feed rates. Inspect the cutting edges and web for wear or chipping before each use and replace the bit if diameter tolerance or point geometry is compromised.