Chicago-latrobe 41728 No 58 Hss Tin Drill Bit 135 Deg

Product Description

The CHICAGO-LATROBE 41728 is a jobber length drill bit designed for precision drilling in metalworking applications. It is manufactured from high speed steel with a titanium nitride (TiN) coating that extends tool life by reducing friction and heat buildup at the cutting edge. The bit measures 0.0420 inches in diameter (No. 58 wire size) with an overall length of 1.625 inches and a flute length of 0.6875 inches. The 135-degree split point angle with web thinning allows for faster penetration and reduces the tendency to walk on hard or smooth surfaces. Licensed HVAC, plumbing, and mechanical trade technicians as well as industrial machinists will find this bit suited to close-tolerance work in ferrous metals.

This drill bit is rated for use in cast iron, stainless steel, and carbon steel workpieces. It fits applications where a small-diameter, high-performance bit is needed for pilot holes, instrument ports, or precise fastener clearances. The straight-cylindrical shank accommodates standard drill chucks and collet holders without modification. The regular spiral flute promotes efficient chip evacuation in both hand-held drills and drill press setups. It conforms to NAS 907 Type B standards, making it appropriate for aerospace-adjacent and precision manufacturing environments.

Key Features

• No. 58 wire size, 0.0420-inch diameter with a diameter tolerance of -0.0005 to 0.0000 inches for tight-tolerance work
• 135-degree split point with web thinning reduces walking and decreases required feed force on hard materials
• Titanium nitride (TiN) coating increases surface hardness and extends bit service life versus uncoated HSS
• Right-hand cut, regular spiral flute with tapered web configuration promotes clean chip flow
• Straight-cylindrical shank fits standard chucks and collets without an adapter
• Meets NAS 907 Type B specification for precision and aerospace-grade drilling applications

Compatibility

Designed as a direct-fit replacement or stock bit for any standard drill chuck or collet accepting a 0.0420-inch straight-cylindrical shank. Primary workpiece materials include cast iron, stainless steel, and carbon steel as listed in the product specifications.

Installation Notes

This bit is installed and serviced by machinists, tool-and-die professionals, and trade technicians using standard drill presses, CNC drilling equipment, or hand-held power drills. Secure the shank fully in the chuck or collet before operation and verify runout is within acceptable limits for the application. Always reduce feed pressure when breaking through the back side of a workpiece to prevent bit deflection or breakage at this small diameter. Proper cutting fluid or coolant is recommended when drilling stainless steel to manage heat, even though this bit does not feature through-coolant capability.