Hertel 74131822 Cobalt Screw Machine Drill Bit Letter I

Product Description

The HERTEL 74131822 is a cobalt screw machine length drill bit designed for high-performance drilling in tough materials. Sized at Letter I (0.2720 inches), it features a 135-degree split point that reduces walking and allows for faster penetration without a center punch. The TiAlN coating increases surface hardness and heat resistance, extending tool life in demanding production and maintenance environments. At 2-11/16 inches overall length, this stub-length bit provides added rigidity compared to jobber-length designs. It is installed by machinists, tool-and-die technicians, and maintenance professionals working with ferrous metals, stainless steel, and high-temperature alloys.

This drill bit is suited for screw machine operations, CNC drilling, and manual drill press work where short overall length reduces deflection and improves hole accuracy. The straight-cylindrical shank fits standard drill chucks across a wide range of machines. It is a practical choice for production shops and industrial maintenance facilities tackling hard metals and abrasive materials that quickly wear high-speed steel tooling.

Key Features

• Letter I size at 0.2720 inches diameter falls within the 0.2500 to 0.3000 inch range
• 135-degree split point reduces thrust and eliminates the need for a center punch on most materials
• TiAlN coating provides heat resistance and extends cutting edge life in hard and abrasive materials
• Cobalt construction resists heat buildup during high-speed or dry drilling operations
• Web-thinned parallel web design improves chip evacuation and reduces torque requirements
• Screw machine (stub) length at 2-11/16 inches overall increases rigidity and minimizes deflection

Compatibility

Designed as an OEM-style replacement and standard tooling option for drill presses, screw machines, and CNC machining centers accepting a straight-cylindrical shank drill bit in the 0.2500 to 0.3000 inch diameter range.

Installation Notes

Installation is performed by machinists and industrial maintenance technicians. Secure the straight-cylindrical shank firmly in a keyed or keyless drill chuck before operation and verify runout is within acceptable tolerance. Ensure the machine is fully stopped and the chuck is locked before bit changes. Coolant through is not supported on this bit, so apply cutting fluid externally when drilling ferrous or stainless materials to manage heat.