Hertel 18551 Countersink 1 in 82 Degree 6 Flute Hss

Product Description

The HERTEL 18551 is a high speed steel countersink designed for producing chamfered recesses in metal, plastic, and composite workpieces. With a 1 inch head diameter and an 82-degree included angle, it creates the precise seat geometry required for flat-head fasteners in aerospace, general machining, and fabrication applications. The 6-flute design distributes cutting load evenly, reducing chatter and improving finish quality in both hand-feed and machine-feed operations. The straight cylindrical shank measures 0.5 inches in diameter, allowing it to seat securely in standard drill chucks and collet holders used in drill presses, lathes, and milling machines.

This countersink is suited for use in machine shops, maintenance facilities, and production environments where consistent chamfer geometry is required. The 82-degree angle matches the industry-standard fastener seat for flat-head machine screws and aerospace-spec hardware. It is intended for use by machinists and tool-and-die professionals working with ferrous and non-ferrous materials. The high speed steel construction handles moderate cutting speeds without requiring carbide tooling upgrades in most general-purpose applications.

Key Features

• 1 inch head diameter for large-diameter chamfer work
• 82-degree included angle matches flat-head fastener seat geometry
• 6 flutes for reduced chatter and improved surface finish
• Straight cylindrical shank at 0.5 inches diameter fits standard chucks and collets
• High speed steel construction provides toughness across a range of workpiece materials
• Tip diameter of 0.203 inches ensures clean entry point initiation

Compatibility

Designed as a direct-fit countersink for standard drill presses, milling machines, and lathes accepting a 0.5 inch straight cylindrical shank. Compatible with drill chucks and ER collet systems sized for 0.5 inch tooling.

Installation Notes

Installation and use should be performed by qualified machinists familiar with rotary cutting tool safety. Secure the shank fully in the chuck or collet before operation and confirm runout is within acceptable tolerance for the application. Power down and lock out the machine before changing or adjusting the tool. Do not exceed the recommended cutting speed range for high speed steel tooling in the workpiece material being machined.