Chicago-latrobe 49393 Screw Machine Drill Bit 0.154 in

Product Description

The CHICAGO-LATROBE 49393 is a screw machine length drill bit designed for high-cycle drilling in metal fabrication, maintenance, and production environments. Built from high speed steel with a coated finish, this bit handles cast iron and steel with a 135-degree split point that reduces walking and cutting force at entry. The shortened screw machine length body improves rigidity in drill press, CNC, and turret lathe applications. With a 0.154 inch diameter matching wire size #23 and a parallel web configuration with web thinning, the 49393 delivers consistent hole geometry and extended service life under heavy-duty use. Diameter tolerance is held to +0.0000 to -0.0007 inches.

This bit is suited for production drilling in ferrous metals, specifically cast iron and steel, in shop and field settings. The screw machine length makes it a preferred choice where stub rigidity is needed but standard jobber length creates deflection issues. Typical install scenarios include CNC machining centers, drill presses, and turret lathes in manufacturing, HVAC fabrication shops, and mechanical contracting environments. The straight-cylindrical shank seats directly in standard drill chucks without adapters. Series 159 designation indicates conformance to NAS 907 specification under NAS standards.

Key Features

• 135-degree split point reduces thrust force and eliminates center punch requirement on most metals
• Web-thinned parallel web for improved chip evacuation and reduced heat buildup
• High speed steel construction with coated finish for extended tool life in ferrous materials
• Screw machine length body increases rigidity and reduces deflection versus jobber length bits
• Right-hand spiral flute geometry with 2 flutes optimized for cast iron and steel
• Diameter tolerance held to +0.0000 to -0.0007 inches for precise hole sizing

Compatibility

Designed as a heavy-duty OEM-style replacement or production drill bit for use in standard straight-shank drill chucks across drill press, CNC, and turret lathe setups. Optimized for primary workpiece materials of cast iron and steel per Series 159 NAS 907 specification.

Installation Notes

Installation and use should be performed by qualified machinists or trade professionals familiar with rotating cutting tools. Secure the straight-cylindrical shank firmly in the chuck and verify runout before drilling. Use appropriate cutting fluid or coolant for extended runs in steel, even though this bit does not feature through-coolant capability. Follow shop safety protocols including eye protection and secure workpiece fixturing before engaging the tool.