Hertel 331-205100 Carbide Countersink 3/8 in 120 Degree 1 Flute

Product Description

The HERTEL 331-205100 is a single-flute carbide countersink designed for creating precise angled seat profiles in metal, composite, and hard materials. With a 3/8 inch head diameter and a 120-degree included angle, it produces clean, accurate countersunk recesses for flathead fasteners in a single pass. The straight cylindrical shank measures 3/8 inch in diameter, making it compatible with standard drill chucks and collet holders. Carbide construction provides superior hardness and wear resistance compared to high-speed steel, extending tool life in demanding production and maintenance applications. This tool is suited for machinists, tool and die technicians, and maintenance professionals working in fabrication and repair environments.

The 331-205100 is used in metalworking, fabrication shops, and maintenance operations where consistent countersink geometry is required. The 120-degree included angle is commonly specified for aerospace-style flathead fasteners and certain sheet metal assemblies. The single-flute design reduces cutting forces and helps maintain accuracy in harder materials or when working with hand-held drilling equipment. It is appropriate for use in both manual and CNC-assisted operations where a 3/8 inch shank toolholder is available.

Key Features

• Carbide construction for extended tool life in hard and abrasive materials
• 120-degree included angle suits aerospace-spec and standard flathead fastener recesses
• Single-flute geometry reduces cutting forces and supports accurate entry
• 3/8 inch straight cylindrical shank fits standard chucks and collet systems
• 3/8 inch head diameter for precise, controlled countersink sizing

Compatibility

Designed as a direct-fit replacement or standard tooling option for applications requiring a 3/8 inch head diameter, 120-degree single-flute carbide countersink with a 3/8 inch straight cylindrical shank.

Installation Notes

Installation and use should be performed by qualified machinists or tooling technicians familiar with rotary cutting tool safety. Secure the shank firmly in a properly sized chuck or collet before operation and verify runout is within acceptable limits. Always wear appropriate eye protection and follow shop safety protocols when operating rotary cutting tools. Inspect the carbide cutting edge for chips or wear before each use and replace the tool if damage is observed.