Chicago-latrobe 49385 Screw Machine Drill Bit 0.18 in Hss

Product Description

The CHICAGO-LATROBE 49385 is a screw machine length drill bit designed for high-speed steel cutting in demanding industrial and trade applications. Built to Series 159 standards, it features a 0.18 inch diameter, a 135-degree split point, and a web-thinned parallel web configuration that reduces thrust and improves chip clearing. The straight-cylindrical shank and two-flute spiral design allow smooth, consistent cutting in tight setups where stub-length tooling is required. NAS 907 specification compliance makes this bit suitable for precision drilling work in both production and maintenance environments.

This bit is rated for use on cast iron and steel workpieces, making it a practical choice for HVAC fabrication, mechanical contractors, pipefitters, and general industrial machinists. The screw machine length — shorter than a jobber-length bit — provides added rigidity and is well suited for drill press, turret lathe, and CNC operations where runout control matters. The coated finish adds surface hardness and helps extend tool life under continuous-duty conditions.

Key Features

• 135-degree split point reduces walking and lowers required feed force
• Web-thinned, parallel web construction improves chip evacuation
• High-speed steel construction handles steel and cast iron workpieces
• Screw machine length provides extra rigidity compared to jobber-length bits
• Right-hand cut spiral flute with straight-cylindrical shank for standard chuck compatibility
• NAS 907 and ISO specification compliance for precision applications

Compatibility

Designed as a direct-fit replacement for Series 159 screw machine length drill bits in standard three-jaw and collet chucks accepting a 0.18 inch straight-cylindrical shank. Primary workpiece compatibility includes cast iron and steel.

Installation Notes

Installation and use should be performed by qualified machinists or trade professionals familiar with rotating cutting tools. Secure the shank fully in the chuck and verify runout before drilling. Always power down the drill press, lathe, or CNC spindle completely before changing or inspecting the bit. Use appropriate cutting fluid for the workpiece material to manage heat buildup and extend tool life.