Hertel 18265 Countersink 5/16 in 90 Degree 1 Flute Hss

Product Description

The HERTEL 18265 is a single-flute countersink designed for creating chamfered seat angles in metal workpieces prior to fastener installation. Machined from high speed steel, this tool delivers consistent cutting performance across a range of ferrous and non-ferrous materials. The 90-degree included angle conforms to the standard fastener head geometry used in most machine screw and bolt applications. With a 5/16-inch head diameter and a straight cylindrical shank of the same diameter, the 18265 fits standard drill chucks and collet holders without adapters. It is suited for metalworking shops, maintenance machinists, and trade professionals performing precision hole prep work.

This countersink is a practical choice for light-duty countersinking tasks in metal fabrication, HVAC equipment assembly, electrical panel work, and general mechanical maintenance. The single-flute geometry minimizes chatter on hand-held drilling equipment and benchtop drill presses, making it effective in situations where setup rigidity is limited. The straight cylindrical shank seats securely in standard three-jaw and keyless chucks, allowing quick tool changes during multi-operation work.

Key Features

• 90-degree included angle matches standard flat-head fastener geometry
• Single-flute design reduces chatter for cleaner seat surfaces
• High speed steel construction provides wear resistance across common metals
• 5/16-inch straight cylindrical shank fits standard drill chucks and collets without adapters
• 5/16-inch head diameter suited for small to medium fastener countersinking tasks

Compatibility

Designed as a standard single-flute countersink for use with drill presses, hand drills, and CNC equipment accepting a 5/16-inch straight cylindrical shank.

Installation Notes

Installation and use should be performed by a qualified machinist or trade professional familiar with rotating cutting tools. Secure the workpiece firmly before operation and ensure the shank is fully seated and tightened in the chuck. Run at appropriate spindle speeds for the workpiece material and tool diameter to avoid overheating the high speed steel cutting edge. Do not exceed the tool's rated cutting diameter or use the tool for lateral milling operations.