Hertel E4039020 Square End Mill 5/16 in 4 Flute Cobalt

Product Description

The HERTEL E4039020 is a 4-flute cobalt square end mill designed for milling ferrous metals, hardened steels, and tough alloys where high-speed steel tooling falls short. Built from M42 cobalt high-speed steel and finished with a TiN (titanium nitride) coating, this end mill delivers extended tool life and improved wear resistance. The cutting diameter is 0.3125 inches (5/16 inch) with a 0.75-inch length of cut, a 0.375-inch shank diameter, and a 2.5-inch overall length. It runs a 30-degree helix spiral flute geometry, is centercutting, and cuts in the right-hand direction with right-hand flutes. Installed by machinists and toolroom technicians, this end mill fits standard CNC machining centers, knee mills, and manual mills.

This end mill is suited for general-purpose slotting, profiling, and plunge cuts in steel, stainless steel, cast iron, and similar materials. The centercutting design allows direct plunge entry without a pre-drilled pilot hole. The TiN coating reduces friction and heat buildup at the cutting edge, extending tool life in production and job-shop environments. The regular-length geometry keeps the setup rigid for accurate dimensional cuts in both horizontal and vertical orientations.

Key Features

• M42 cobalt HSS construction for cutting hardened and tough ferrous materials
• TiN finish for improved wear resistance and reduced cutting friction
• 4-flute spiral design with 30-degree helix for balanced chip evacuation and surface finish
• Centercutting geometry allows direct plunge milling without a pilot hole
• Right-hand cut and right-hand flute configuration for standard spindle use
• Regular-length geometry promotes rigidity and dimensional accuracy

Compatibility

Designed as an OEM-style replacement or direct-use cutting tool compatible with standard milling machines and CNC machining centers accepting a 3/8-inch straight shank end mill holder or collet.

Installation Notes

Installation and use of this end mill should be performed by qualified machinists or toolroom technicians. Confirm spindle speed and feed rate from published cobalt end mill cutting data for the specific workpiece material before use. Secure the shank fully in a clean, properly sized collet or end mill holder and verify runout before engaging the cut. Inspect the cutting edges for wear or chipping after each use and replace the tool before edge condition degrades part quality.