Hertel 18606 Countersink 5/16 in 82 Deg 4 Flute Hss

Product Description

The HERTEL 18606 is a single-pass countersink designed for producing clean, chamfered seat openings in metal and other machinable materials. Built from high speed steel, it features a 5/16-inch head diameter and an 82-degree included angle — the standard angle for flat-head fastener seating in most North American applications. The 4-flute geometry distributes cutting load evenly, reducing chatter and producing a smoother finish compared to single- or double-flute designs. The straight cylindrical shank measures 1/4 inch in diameter, making it compatible with standard drill chucks and quick-change tooling. Machinists, tool-and-die technicians, and general metalworking shops use this countersink for production and maintenance work.

This countersink is suited for bench drill press, CNC, and hand drill applications where flat-head screw recesses are required. The 82-degree angle matches the seating geometry of most imperial flat-head machine screws and sheet-metal screws. It is appropriate for use in light-gauge steel, aluminum, brass, and similar materials where high speed steel tooling performs reliably. The 1/4-inch shank allows direct use in standard collets and keyless chucks without an adapter in most setups.

Key Features

• 82-degree included angle matches standard imperial flat-head fastener geometry
• 4-flute design reduces chatter and improves surface finish in the countersunk seat
• High speed steel construction provides durability across a range of machinable materials
• 5/16-inch head diameter suitable for common small-to-medium fastener sizes
• Straight cylindrical 1/4-inch shank fits standard drill chucks and collets without modification

Compatibility

Designed as an OEM-style replacement or direct-use countersink for applications requiring an 82-degree, 4-flute, 5/16-inch head diameter tool with a 1/4-inch straight cylindrical shank.

Installation Notes

Install and remove this countersink with the machine fully powered down and the spindle at rest. Secure the 1/4-inch shank firmly in the chuck before operation to prevent runout. Use appropriate cutting fluid for harder metals to extend tool life and improve finish quality. Follow applicable shop safety standards when operating drill press or CNC equipment.