Hertel 18540 Countersink 3/4 in 100 Deg 6 Flute Hss

Product Description

The HERTEL 18540 is a single-unit countersink designed for creating clean, beveled seat profiles in metal workpieces. It features a 3/4-inch head diameter and a 100-degree included angle, making it suited for applications where fastener heads require a wider seating angle than the standard 82-degree configuration. The 6-flute design distributes cutting load evenly, reducing chatter and improving surface finish. The body is manufactured from high speed steel (HSS), providing adequate hardness and wear resistance for production drilling in mild steels, aluminum, and similar materials. A straight-cylindrical 1/2-inch shank fits standard drill chucks and milling machine tool holders.

This countersink is used in machine shops, fabrication facilities, and maintenance environments where machinists and tooling technicians need to prep holes for flush or near-flush fastener installation. The 100-degree included angle is commonly specified for aerospace-style or metric fastener applications. It is appropriate for bench drill press work, CNC machining centers, and manual milling setups where a 1/2-inch shank tool holder is available. Sold as a single piece.

Key Features

• 3/4-inch head diameter for moderate to large hole chamfering
• 100-degree included angle suits wider-seat fastener specifications
• 6 flutes reduce chatter and improve cut finish quality
• High speed steel construction provides durability in ferrous and non-ferrous materials
• Straight-cylindrical 1/2-inch shank for broad tool holder compatibility

Compatibility

Designed as an OEM-style single-piece countersink for use in any drill press, CNC machining center, or manual mill equipped with a 1/2-inch straight-shank tool holder or drill chuck.

Installation Notes

Installation is performed by qualified machinists or tooling technicians. Secure the shank fully in a properly rated 1/2-inch chuck or collet before operation, and confirm the tool holder is locked before starting the spindle. Run at appropriate surface footage for the workpiece material and use cutting fluid when working in steel to extend tool life. Inspect flute edges for wear or chipping before each use and remove from service if damage is observed.