Hertel 74131038 Cobalt Screw Machine Drill Bit Size 51

Product Description

The HERTEL 74131038 is a cobalt screw machine length drill bit designed for high-speed drilling in tough materials. It carries a wire gauge size of 51, corresponding to a decimal diameter of 0.0670 inches, and features a 135-degree split point that reduces walking and allows drilling to start without a center punch. The overall length is 1-11/16 inches, making it a stub-length tool suited for rigid setups in drill presses, CNC machines, and screw machine operations. The right-hand, regular spiral flute geometry provides efficient chip evacuation. This bit is sold individually but requires a minimum order of 12 units.

Screw machine length drill bits are used where a short, stiff tool is required to minimize deflection and maintain tight tolerances. This bit is appropriate for production drilling, repetitive hole operations, and applications involving hardened steels, stainless steel, cast iron, and other difficult-to-machine materials where cobalt steel offers a clear advantage over standard high-speed steel. It fits standard straight-shank chucks and is well-suited for machine shop, manufacturing, and maintenance environments where consistent hole quality matters.

Key Features

• Cobalt steel construction for extended tool life in hard and abrasive materials
• 135-degree split point reduces thrust force and eliminates center-punch requirement
• Web-thinned parallel web for improved cutting efficiency and reduced heat buildup
• Screw machine (stub) length at 1-11/16 inches overall provides maximum rigidity and reduced runout
• Regular spiral flute with 11/16-inch flute length promotes clean chip evacuation in short-hole applications
• Straight cylindrical shank fits standard drill chucks without requiring a specialty holder

Compatibility

Designed for use in standard straight-shank drill chucks on drill presses, CNC machining centers, and automatic screw machines. Suitable for wire gauge size 51 applications across the 0.0000 to 0.1000 inch decimal inch drill size range as defined by the HSCO135 series.

Installation Notes

This bit is installed by machinists and tool-and-die professionals in machine shop and production environments. Secure the shank fully in a properly sized collet or drill chuck before operation and verify runout is within acceptable limits. Always power down and lock out the machine spindle before changing tooling. Do not exceed the recommended feed and speed parameters for cobalt bits in the target material, and allow adequate chip clearance during drilling to prevent flute packing.