Hertel 74147729 Cobalt Drill Bit 31/32 in 1/2 in Shank

Product Description

The HERTEL 74147729 is a reduced shank cobalt drill bit designed for drilling into tough, high tensile strength materials where standard high-speed steel bits wear prematurely. The bit measures 31/32 inches in diameter with a 1/2-inch straight-cylindrical shank, allowing it to run in standard 1/2-inch chuck equipment despite the larger cutting diameter. Overall length is 6 inches with a 3-inch spiral flute. The 118-degree standard point angle suits general-purpose drilling in ferrous and hard alloy workpieces. An oxide straw finish provides light corrosion resistance and reduces friction at the cutting edge. Right-hand cut. Licensed machinists, tool-and-die workers, and maintenance mechanics rely on cobalt construction for extended tool life in demanding materials.

This drill bit is suited for production and maintenance drilling applications where the workpiece material is a tough, high tensile strength alloy, stainless steel, or similar hard ferrous metal. The reduced shank design makes a larger-diameter bit accessible to any machine or hand drill equipped with a 1/2-inch chuck, eliminating the need for a larger Jacobs-taper chuck setup. It is appropriate for use on drill presses, lathes, and heavy-duty hand drills in industrial, manufacturing, and fabrication environments. Coolant-through is not supported; external coolant or cutting fluid applied at the workpiece is recommended for extended runs.

Key Features

• Cobalt tool material resists heat and wear when drilling tough, high tensile strength metals
• 118-degree standard point angle for general-purpose drilling in ferrous materials
• Reduced 1/2-inch straight-cylindrical shank fits standard 1/2-inch chucks on drill presses and hand drills
• 3-inch spiral flute length with regular spiral for efficient chip evacuation
• Oxide straw finish reduces friction and provides light corrosion protection
• Right-hand cut configuration compatible with conventional drilling equipment

Compatibility

Designed as an OEM-style replacement or direct-use cobalt drill bit for any drill press, CNC drilling machine, or heavy-duty hand drill equipped with a 1/2-inch chuck capacity.

Installation Notes

Installation and use should be performed by a qualified machinist or maintenance technician familiar with metal-cutting operations. Secure the workpiece firmly before drilling and confirm the chuck is fully tightened on the 1/2-inch shank before operation. Power down and de-energize the machine before changing or inspecting the bit. Apply a suitable cutting fluid or oil to the cutting zone when drilling hard alloys to extend tool life and prevent heat buildup; this bit does not support internal coolant delivery.