Hertel 74130428 Cobalt Drill Bit 31/64 Inch 135 Degree

Product Description

The HERTEL 74130428 is a screw machine length drill bit designed for high-speed, high-heat drilling applications in metal and other hard materials. Built from cobalt high-speed steel (HSCO), this bit resists heat buildup that would degrade standard HSS tooling. The 135-degree split point starts on contact without a center punch, reducing walking and improving hole accuracy. At 3-11/16 inches overall length, the screw machine format provides added rigidity over jobber-length bits, making it well suited for drill press, turret lathe, and CNC screw machine work where short, stiff tooling controls runout and improves finish.

This bit is used primarily in metalworking and machining environments where stainless steel, high-alloy steel, cast iron, or other tough materials are drilled at high cycle rates. The shorter overall length and parallel web configuration make it a common choice for production machining and repair shops. It is equally applicable on manual drill presses and automated equipment. Machinists, tool-and-die technicians, and maintenance trades install and use this type of bit regularly.

Key Features

• Cobalt HSCO construction for heat resistance in hard and abrasive materials
• 135-degree split point for self-centering starts and reduced thrust
• Web-thinned parallel web for improved chip evacuation and cutting efficiency
• Screw machine length at 3-11/16 inches overall for maximum rigidity and runout control
• Regular spiral flute with 2-3/16 inch flute length for consistent chip flow
• Straight cylindrical shank fits standard drill chucks without adapters
• Right-hand cutting direction for standard drill press and CNC spindle rotation

Compatibility

Designed as a direct-fit screw machine length drill bit for standard drill chucks and collet holders accepting a straight cylindrical shank in the 0.4500 to 0.5000 decimal inch diameter range.

Installation Notes

This bit is installed and used by machinists and maintenance technicians on drill presses, lathes, and CNC equipment. Secure the straight shank fully in a properly sized chuck or collet before operation. Ensure the machine spindle is at a complete stop before changing or inspecting bits. Use appropriate cutting fluid for the workpiece material to extend bit life and maintain hole tolerance.