Chicago-latrobe 49429 Screw Machine Drill Bit 0.041 in

Product Description

The CHICAGO-LATROBE 49429 is a screw machine length drill bit designed for high-production drilling in metal fabrication and machining applications. Built from high speed steel with a coated finish, this bit measures 0.041 inches in diameter (Wire Size 59) and features a 135-degree split point for self-centering starts and reduced thrust. The shortened screw machine length body improves rigidity in drill press and CNC turret setups, making it a reliable choice for machinists and tool room technicians working in tight tolerances. It carries a diameter tolerance of +0.0000 to -0.0005 inches, which supports precision hole sizing in production runs.

This drill bit is suited for drilling cast iron and steel in screw machine, turret lathe, and CNC drilling operations where stub-length rigidity is preferred over jobber-length reach. The regular spiral flute and parallel web configuration provide consistent chip evacuation in moderate-depth holes. The straight cylindrical shank seats directly into standard drill chucks without an adapter. It conforms to NAS 907 specification under NAS designation, making it appropriate for aerospace-adjacent and industrial manufacturing environments where specification compliance is required.

Key Features

• 0.041 inches diameter, Wire Size 59, with tight tolerance of +0.0000 to -0.0005 inches for precision fitment
• 135-degree split point reduces walking and lowers required thrust at entry
• Screw machine (stub) length body increases rigidity and reduces deflection in short-reach applications
• High speed steel construction with coated finish for extended wear life in ferrous materials
• Right-hand cut, 2-flute regular spiral design promotes clean chip removal from cast iron and steel
• Web-thinned parallel web reduces cutting resistance and improves penetration rate
• Meets NAS 907 specification under NAS designation for use in specification-controlled environments

Compatibility

Designed as a screw machine length replacement drill bit for production drilling into cast iron and steel workpieces. Compatible with standard drill chucks accepting a 0.041-inch straight cylindrical shank.

Installation Notes

Installation and use of this drill bit should be performed by qualified machinists or tool room technicians familiar with drill press, turret lathe, or CNC drilling equipment. Secure the straight cylindrical shank firmly in the drill chuck and verify runout before beginning a production run. Always wear appropriate eye protection and follow the machine manufacturer guidelines for spindle speed selection based on workpiece material and hole diameter. Replace the bit when cutting performance degrades or visible wear on the cutting edges is observed.