Hertel 04139440 Cobalt Jobber Drill Bit Letter Q

Product Description

The HERTEL 04139440 is a cobalt jobber-length drill bit sized to Letter Q (0.3320 inches decimal equivalent) with a 135-degree split point and web-thinned geometry. Designed for heavy-duty holemaking in ferrous metals, stainless steel, and other hard materials, it features a spiral flute in a regular helix and an oxide finish. The straight-cylindrical shank measures 0.3320 inches in diameter, and the overall length is 4.75 inches with a flute length of 3.4375 inches. Right-hand cutting direction. Installed by machinists, maintenance technicians, pipefitters, and general contractors requiring consistent, accurate holes in tough substrates.

This drill bit is suited for production and maintenance drilling applications where cobalt construction provides heat resistance and edge retention beyond standard high-speed steel. The 135-degree split point reduces walking on entry and lowers thrust requirements, making it practical for hand drilling and drill-press work alike. The oxide coating adds lubricity and light corrosion resistance during use. Typical applications include drilling through structural steel, cast iron, pipe, and heavy plate in industrial maintenance, fabrication, and mechanical contracting environments.

Key Features

• Letter Q size with 0.3320-inch decimal equivalent for precise fitment to fastener and reaming sequences
• 135-degree split point with web thinning reduces entry walking and cutting thrust
• Cobalt construction provides heat resistance and edge retention in hard and abrasive materials
• Oxide finish adds surface lubricity and light corrosion protection
• Regular spiral flute with tapered web configuration promotes efficient chip evacuation
• Straight-cylindrical shank is compatible with standard drill chucks and collets

Compatibility

Designed as a heavy-duty jobber-series drill bit for use in standard drill chucks and collets accepting a 0.3320-inch straight-cylindrical shank, suitable for drill presses, hand drills, and CNC drilling operations.

Installation Notes

Install in a properly rated drill chuck or collet appropriate for the shank diameter before applying power. Secure the workpiece firmly before drilling to prevent movement. Use appropriate cutting fluid or coolant for the material being drilled to extend edge life and improve hole quality. Follow applicable shop safety standards and wear appropriate PPE including eye protection during all drilling operations.