Hertel 74131178 Drill Bit Letter F Cobalt Split Point

Product Description

The HERTEL 74131178 is a cobalt screw machine length drill bit in Letter F size (0.2570 inches decimal equivalent), designed for drilling into hard and abrasive materials including stainless steel, high-strength alloys, and hardened steels. The 135-degree split point geometry reduces walking and requires less feed pressure at the start of the cut. A web-thinned, parallel web construction improves chip evacuation and reduces axial thrust. At 2.625 inches overall length, this is a stub-length format intended for rigid, close-tolerance drilling in machine-tool and production environments. Machinists and tool-room technicians are the primary users.

This bit is suited for CNC machining centers, drill presses, and hand-held production drilling where short bit length minimizes deflection. It fits applications in metalworking, fabrication shops, and MRO environments requiring a right-hand, regular spiral flute bit in the 0.2500 to 0.3000 inch diameter range. The straight cylindrical shank seats in standard Jacobs-style chucks and collet holders sized for this diameter class.

Key Features

• Letter F size - 0.2570 inch decimal equivalent, within the 0.2500 to 0.3000 inch range
• Cobalt high-speed steel (HSCO) construction for heat and wear resistance in hard materials
• 135-degree split point reduces drill walk and lowers required feed force
• Web-thinned parallel web design improves chip flow and reduces thrust load
• Screw machine (stub) length - 2.625 inches OAL - maximizes rigidity and minimizes deflection
• Right-hand cut, regular spiral flute with straight cylindrical shank for broad chuck compatibility

Compatibility

Designed as an OEM-style replacement or direct-use cobalt stub drill for metalworking applications in the 0.2500 to 0.3000 inch drill size range, fitting standard straight-shank drill chucks and collet holders.

Installation Notes

Installation and use of this drill bit should be performed by qualified machinists or toolroom technicians familiar with metal-cutting operations. Ensure the drill press, CNC spindle, or hand drill is fully powered down and locked out before changing bits. Seat the straight shank fully in the chuck or collet and verify tightness before initiating a cut. Do not exceed the rated speed and feed parameters for cobalt tooling in the work material being drilled.