Hertel E4039903 Square End Mill 7/16 in 4 Flute Cobalt

Product Description

The HERTEL E4039903 is a 4-flute cobalt square end mill designed for milling ferrous metals, stainless steels, and other tough materials in CNC and manual machining applications. Built from M42 cobalt high-speed steel and finished with a TiN (titanium nitride) coating, it delivers increased surface hardness and heat resistance compared to standard HSS tooling. The cutter measures 7/16 inches in diameter with a 3/8-inch shank, a 1-inch length of cut, and a 2-11/16-inch overall length. A 30-degree helix angle and spiral flute geometry promote efficient chip evacuation and smooth cutting action. This is a right-hand cut, right-hand flute tool in a regular-length configuration.

This end mill is suited for slotting, profiling, and peripheral milling operations in job shops, tool rooms, and production environments. Its centercutting design allows direct plunge entry into the workpiece without a pre-drilled hole, adding flexibility in milling setups. The 3/8-inch shank fits standard ER collet chucks, end mill holders, and Weldon-style tool holders commonly found in vertical machining centers and knee mills. It is appropriate for machinists, tool-and-die makers, and CNC operators handling medium-duty cutting tasks.

Key Features

• M42 cobalt HSS construction for improved heat and wear resistance over standard M2 HSS
• TiN finish increases surface hardness and extends tool life in ferrous materials
• Centercutting design permits direct plunge milling without pilot drilling
• 30-degree helix angle with spiral flutes for effective chip evacuation
• Right-hand cut and right-hand flute orientation — standard configuration for most mills
• Regular-length geometry provides rigidity for stable milling in typical depth-of-cut applications

Compatibility

Designed as a direct-fit replacement or standard tooling selection for any setup requiring a 3/8-inch shank, 7/16-inch diameter, 4-flute square end mill in ER collet chucks, end mill holders, or Weldon-style tool holders.

Installation Notes

Installation should be performed by a qualified machinist or CNC operator following the machine tool manufacturer's tooling guidelines. Ensure the spindle is fully stopped and the machine is in an energy-isolated state before changing tooling. Seat the shank fully into the tool holder and tighten to the holder manufacturer's specified clamping torque using the appropriate wrench — do not use makeshift tools that may under- or over-clamp. Verify runout with a dial indicator after installation before beginning any cutting operation.