Hertel E2051016 Square End Mill 0.25 in 4 Flute Cobalt

Product Description

The HERTEL E2051016 is a cobalt square end mill designed for milling operations in ferrous and tough alloy materials. Built from M42 cobalt high-speed steel, it resists heat buildup during aggressive cuts. The tool measures 0.25 inches in cutting diameter with a 0.625-inch length of cut, a 0.375-inch shank diameter, and a 3.375-inch overall length. The 4-flute, 30-degree right-hand spiral configuration provides efficient chip evacuation and a smooth surface finish. This is an uncoated, double-end design, allowing the tool to be flipped and reused once one end wears. Licensed machinists and tool-and-die professionals typically select this end mill for standard-reach slotting and peripheral milling tasks.

The E2051016 is suited for use in manual mills and CNC machining centers handling steel, stainless steel, cast iron, and similar materials where cobalt tooling provides the edge retention that standard HSS cannot sustain. The regular-length profile fits conventional tool holders and collet chucks with a 0.375-inch bore. This end mill is a practical choice for job shops, maintenance machining, and production environments where tool longevity under heat is a priority. It is not center-cutting, so it is not intended for direct plunge operations.

Key Features

• M42 cobalt construction for improved heat resistance and edge retention over standard HSS
• Double-end design extends usable tool life — flip when first end wears
• 4-flute spiral geometry with 30-degree helix angle for smooth finish and efficient chip flow
• Right-hand cut and right-hand flute for use in standard spindle configurations
• Uncoated surface — compatible with cutting fluids and oils without coating delamination concerns
• Not center-cutting — intended for peripheral milling and slotting, not plunge entry

Compatibility

Designed as an OEM-style replacement or direct-use square end mill for standard 0.375-inch collet chucks, end mill holders, and tool blocks used in vertical and horizontal milling machines.

Installation Notes

Installation is performed by qualified machinists or tooling technicians. Ensure the machine spindle is fully stopped and the drawbar or collet nut is fully released before inserting or removing the tool. Seat the shank to the full recommended depth in the holder and torque the collet nut or set screw to the holder manufacturer's specification. Verify runout with a dial indicator before commencing a cut, as excessive runout accelerates edge wear and degrades surface finish.