Hertel 04139499 Cobalt Jobber Drill Bit Letter V

Product Description

The HERTEL 04139499 is a cobalt jobber-length drill bit sized to Letter V (0.3770 inches) with a 135-degree split point and oxide/gold coating. Designed for heavy-duty holemaking in ferrous and hard materials, this bit features a right-hand spiral flute, web-thinned geometry, and a straight-cylindrical shank. The split point reduces walking at drill entry and lowers thrust force, which is important when drilling tough alloys, stainless steel, or hardened stock. Cobalt construction provides heat resistance beyond standard high-speed steel, making this bit suitable for production drilling and demanding shop environments where tool life is critical.

This drill bit fits standard jobber drilling applications in machining, fabrication, maintenance, and repair operations. The straight-cylindrical shank seats directly in conventional three-jaw drill chucks on drill presses, CNC machining centers, and handheld power drills. The 5-inch overall length and 3-5/8-inch flute length are typical for Letter V jobber work in general-purpose and structural holemaking tasks. No coolant-through capability, so external cutting fluid or spray mist cooling is the appropriate approach in high-feed applications.

Key Features

• Letter V size: 0.3770 inches diameter for precise fractional and letter-series drilling
• 135-degree split point reduces thrust and prevents bit walking on entry
• Cobalt construction for elevated heat resistance and extended tool life in hard materials
• Oxide and TiN coating improves surface hardness and lubricity
• Web-thinned, tapered web design lowers cutting resistance and chip clearance
• Right-hand spiral flute with regular helix for efficient chip evacuation

Compatibility

Designed as a standard jobber-series drill bit for use in any three-jaw chuck or collet system accepting a 0.3770-inch straight-cylindrical shank, compatible with drill presses, manual mills, and handheld power tools in that bore range.

Installation Notes

A licensed machinist or qualified tradesperson should secure the shank fully in a properly sized chuck before operation. Ensure the drilling machine is powered down and de-energized before installing or removing the bit. Apply cutting fluid or mist coolant externally when drilling hard alloys to manage heat buildup, as this bit does not support coolant-through delivery. Inspect the cutting edges for wear or chipping before each use and replace when point geometry is compromised.