Hertel 18643 Countersink 5/8 in 90 Degree 4 Flute Hss

Product Description

The HERTEL 18643 is a straight-shank countersink designed for producing clean, accurately angled seat bores in metal, plastic, and composite materials. Built from high speed steel, it features a 90-degree included angle and four flutes, delivering smooth chip evacuation and consistent finish quality in both hand-drill and machine applications. With a 5/8-inch head diameter and a 3/8-inch straight cylindrical shank, this countersink fits standard drill chucks and collet holders commonly found on drill presses, CNC machines, and hand drills. It is suited for machinists, fabricators, and maintenance technicians who require reliable countersinking for fastener seating and deburring tasks.

This countersink is appropriate for light to medium-duty production and maintenance work across general fabrication shops, machine shops, and field service environments. The 90-degree included angle matches the standard seating angle for flat-head machine screws and similar fasteners, making it a practical choice for ferrous and non-ferrous metalwork, as well as plastics. The four-flute geometry provides good surface finish and control at moderate feed rates on manual and CNC drilling equipment.

Key Features

• 5/8-inch head diameter provides adequate countersink depth for common flat-head fastener sizes
• 90-degree included angle matches standard flat-head screw seating geometry
• Four-flute design promotes smooth chip flow and consistent finish
• High speed steel construction offers durability across a range of workpiece materials
• 3/8-inch straight cylindrical shank fits standard drill chucks and collet holders

Compatibility

Designed as a general-purpose countersink compatible with standard 3/8-inch drill chucks and collet holders on drill presses, hand drills, and CNC drilling equipment.

Installation Notes

Installation and use should be performed by machinists or trained technicians familiar with rotary cutting tools. Secure the workpiece firmly before operation and verify the shank is fully seated and clamped in the chuck or collet before running the spindle. Use appropriate cutting fluid for ferrous materials to extend tool life and improve finish. Follow shop-standard speeds and feeds for high speed steel tooling in the workpiece material being machined.