Chicago-latrobe 44394 Drill Bit Letter X 0.3970 in Hss

Product Description

The CHICAGO-LATROBE 44394 is a jobber length drill bit sized to Letter X (0.3970 inches decimal) and manufactured from high speed steel with a bright uncoated finish. It features a 118-degree standard point angle and a web-thinned, tapered web configuration that reduces thrust and improves chip evacuation at the drill entry point. The two-flute regular spiral geometry moves chips efficiently out of the hole. At 5.125 inches overall length with a 3.75-inch flute, this bit fits standard three-jaw drill chucks and is sized for general-purpose production and maintenance drilling tasks performed by machinists, pipefitters, and mechanical contractors.

The 44394 is designed for drilling non-ferrous metals and general-purpose materials in both shop and field applications. The straight cylindrical shank at 0.3970 inches diameter seats directly in standard drill chucks without adapters. Its Series 150D construction meets DIN 338 standards, making it a recognized benchmark geometry for jobber-length tooling used in fabrication shops, mechanical rooms, and on-site installation work where consistent, repeatable hole size matters.

Key Features

• Letter X size — 0.3970 inches decimal equivalent for precise hole sizing
• 118-degree standard point angle with web-thinned, tapered web for reduced entry thrust
• High speed steel construction — suitable for general-purpose and non-ferrous drilling
• Bright uncoated finish — allows direct visual inspection of bit condition
• Regular two-flute spiral geometry promotes efficient chip removal
• Straight cylindrical shank fits standard drill chucks without adapters
• Meets DIN 338 jobber-length standard — Series 150D

Compatibility

Designed as an OEM-style general-purpose jobber length drill bit suitable for use in standard drill presses, hand drills, and CNC drilling equipment accepting a 0.3970-inch straight cylindrical shank.

Installation Notes

Installation and use should be performed by qualified machinists or trade professionals familiar with rotating cutting tools. Secure the shank fully within the chuck and verify the chuck key is removed before powering the drill. Always wear appropriate eye protection and secure the workpiece before beginning the cut. Cutting speeds should be selected based on workpiece material and machine capability in accordance with standard machining practice.