Chicago-latrobe 41721 Jobber Drill Bit 51 Hss Tin 135 Deg

Product Description

The CHICAGO-LATROBE 41721 is a jobber-length drill bit in wire gauge size 51 (0.0670 inches decimal), manufactured from high speed steel with a titanium nitride (TiN) coating. It features a 135-degree split point for fast, accurate starts without a center punch and a regular spiral flute design for efficient chip evacuation. Overall length is 2 inches, with a 1-inch flute length and a straight-cylindrical shank. Web thinning reduces thrust load at the tip. This is a heavy-duty, high-performance bit suited for production drilling and general metalworking applications where small-diameter precision holes are required.

This bit is designed for drilling cast iron, stainless steel, and steel in demanding shop and field environments. The 150ASP-TN series is built to NAS 907 Type B standards, making it appropriate for aerospace-adjacent and precision machining work. Right-hand cutting direction and a 2-flute spiral configuration make it compatible with standard drill presses, CNC machining centers, and hand-held electric drills. Machinists, tool-and-die workers, and HVAC or plumbing tradespeople drilling small pilot or clearance holes in metal will find this size useful for fastener and fitting work.

Key Features

• Wire gauge size 51 with 0.0670-inch decimal diameter for small-diameter precision drilling
• 135-degree split point reduces walking and eliminates the need for a center punch on flat stock
• Titanium nitride (TiN) coating increases surface hardness and extends cutting life compared to uncoated HSS
• Web-thinned, tapered web reduces axial thrust and improves chip flow
• Right-hand, 2-flute regular spiral design works with standard drill presses and portable drills
• Meets NAS 907 Type B specification for heavy-duty, high-performance applications

Compatibility

Designed for drilling cast iron, stainless steel, and steel workpieces. Fits any standard drill chuck accepting a straight-cylindrical shank at 0.0670-inch diameter. Part of the CHICAGO-LATROBE 150ASP-TN series, which covers the 0.0500 to 0.1000-inch decimal inch size range.

Installation Notes

Machinists and metalworkers should ensure the drill chuck is fully tightened and the workpiece is securely clamped before drilling. Use appropriate cutting fluid or coolant when drilling stainless steel or hardened steel to extend bit life and prevent work hardening. Run at the correct SFM for the workpiece material and bit diameter — small-diameter bits are sensitive to excess feed pressure and side loading. Inspect the cutting edges before each use; a chipped split point will cause wandering and oversized holes.