Hertel 79892527 Solid Carbide Jobber Drill Letter E

Product Description

The HERTEL 79892527 is a solid carbide jobber-length drill bit sized at Letter E (0.2500 inches) with a 118-degree standard point angle. Ground from C2-grade solid carbide, it delivers the rigidity and wear resistance needed for drilling hard and abrasive materials where high-speed steel bits lose edge retention too quickly. The web-thinned, tapered web design reduces thrust at entry and improves chip evacuation. At 3.25 inches overall length with a 2-inch flute, this is a standard jobber proportion suited to general-purpose production and maintenance drilling. The straight 0.2500-inch shank seats directly in standard drill chucks without adapters.

This bit is intended for use in CNC machining centers, drill presses, and hand-held power drills where a solid carbide substrate is preferred over coated HSS. Typical applications include drilling ferrous alloys, cast iron, hardened steels, and composites in shop, tool room, and field maintenance settings. The right-hand cutting direction and regular spiral flute geometry are compatible with conventional drilling setups. No coolant-through capability means external coolant or dry cutting applies. Machinists, tool and die makers, and maintenance technicians are the primary users of this bit.

Key Features

• Solid carbide construction (C2 grade) for superior hardness and wear resistance vs. HSS
• 118-degree standard point angle with web-thinned, tapered web for reduced entry thrust
• Letter E size: 0.2500 inches diameter, tolerance -0.0005 to 0.0000 inches
• 2-inch flute length with regular right-hand spiral for consistent chip removal
• Bright/uncoated finish — no coating buildup concerns on regrind
• Straight 0.2500-inch shank fits standard drill chucks directly

Compatibility

Designed as a general-purpose solid carbide jobber drill for use in any standard drill chuck or collet accepting a 0.2500-inch straight shank. No specific system or machine compatibility is stated by the manufacturer for this part number.

Installation Notes

A licensed machinist or qualified maintenance technician should secure the shank fully in the chuck or collet before operation, verifying runout with a dial indicator when precision hole tolerance is required. Ensure the drilling machine is powered down and de-energized before changing bits. Because this bit has no coolant-through capability, apply external coolant or cutting fluid at the cutting zone when drilling ferrous metals to manage heat. Avoid side loading or interrupted cuts that can fracture the carbide substrate.