Hertel 04618690 Stub Drill Bit No. 12 Cobalt Oxide

Product Description

The HERTEL 04618690 is a cobalt stub-length drill bit designed for drilling into high-tensile-strength metals. It carries a No. 12 wire gauge size with a decimal equivalent of 0.1890 inches and an overall length of 0.5625 inches, making it a compact tool suited for close-quarter drilling applications. The 135-degree split point geometry self-centers on contact, reducing the need for a center punch and minimizing walking on hard surfaces. A tapered, web-thinned construction lowers thrust requirements when penetrating tough alloys. The oxide coating adds a measure of surface hardness and corrosion resistance. Right-hand spiral flutes with a regular helix clear chips efficiently during the cut. This bit is installed and used by machinists, aerospace maintenance technicians, and industrial trade professionals.

This bit is built for use in high-tensile-strength metal applications including alloy steel, stainless steel, and similarly hard materials where standard high-speed steel tooling dulls prematurely. The 1/4-28 threaded square shank is designed to seat in compatible threaded-shank drilling equipment. The stub length reduces deflection in tight or blind-hole scenarios. It meets NAS 965 Type D specification, making it appropriate for aerospace and precision industrial maintenance work where dimensional and geometry standards are required.

Key Features

• No. 12 wire size, 0.1890-inch decimal diameter for precise hole sizing
• 135-degree split point with web thinning for self-centering and reduced thrust
• Cobalt construction with oxide coating for performance in high-tensile-strength metals
• Stub length at 0.5625 inches overall reduces deflection in confined areas
• 1/4-28 threaded square shank for compatibility with threaded-shank tooling systems
• Right-hand spiral flutes with regular helix for efficient chip evacuation
• Meets NAS 965 Type D specification

Compatibility

Designed for use with threaded-shank drilling equipment accepting a 1/4-28 shank connection. Intended for drilling high-tensile-strength metals per NAS 965 Type D specification requirements.

Installation Notes

This bit is installed by machinists and maintenance technicians using compatible threaded-shank drill motors or holders. Ensure the spindle and shank threads are clean and fully engaged before operation. Always secure the workpiece and use appropriate cutting fluid when drilling hard alloys to extend tool life and maintain hole quality. Inspect the cutting edges before each use and replace the bit if chipping or wear is detected.