Hertel 18261 Countersink 1/4 in Hss 100 Degree 1 Flute

Product Description

The HERTEL 18261 is a single-flute countersink designed for creating clean, conical seat profiles in metal and other materials. It features a 1/4 inch head diameter, a 100-degree included angle, and a straight-cylindrical 1/4 inch shank. Constructed from high speed steel (HSS), it delivers adequate hardness and wear resistance for general-purpose countersinking operations. Machinists, toolmakers, and maintenance technicians use this tool in drill presses, lathes, and hand-held power drills where a controlled, burr-free countersink is required for fastener seating or deburring.

This countersink is suited for use in job shops, manufacturing facilities, and maintenance environments where standard 100-degree countersunk fastener holes are required. The 1-flute design produces a smooth finish and reduces chatter, making it effective for softer metals such as aluminum, brass, and mild steel. Its compact 1/4 inch head and matching 1/4 inch shank allow use in a wide range of toolholders and chuck sizes commonly found in light-duty machine shop setups.

Key Features

• 100-degree included angle suits standard countersunk fastener specifications
• Single-flute geometry reduces chatter and produces a smooth surface finish
• High speed steel construction provides hardness suitable for general metalworking applications
• 1/4 inch straight-cylindrical shank fits standard chucks and toolholders
• Compact 1/4 inch head diameter for use in tight or precision applications

Compatibility

Designed as a general-purpose countersink for use with standard 1/4 inch chucks and straight-shank toolholders in drill presses, lathes, and handheld power tools where a 100-degree countersink profile is required.

Installation Notes

This tool is installed by machinists or maintenance technicians into a drill press, lathe tailstock, or handheld drill with a compatible chuck. Secure the shank fully in the chuck before operation and confirm the workpiece is clamped or fixtured to prevent movement. Use appropriate cutting fluid when working with ferrous metals to extend tool life. Inspect the cutting edge for wear or chipping before each use.