Hertel 06821664 Roughing End Mill 3/8 in 4 Flute Cobalt

Product Description

The HERTEL 06821664 is a single-end roughing end mill designed for aggressive material removal in milling operations. Built from M42 cobalt high-speed steel with a bright, uncoated finish, this tool handles tough ferrous and non-ferrous materials where standard HSS cutters wear prematurely. The 3/8 inch cutting diameter and 4-flute configuration produce a coarse chip-breaking action along the 3/4 inch length of cut, reducing chatter and heat buildup during roughing passes. With a 2.5 inch overall length and matching 3/8 inch shank, it fits standard collets and end mill holders on vertical mills and machining centers. Right-hand cutting and right-hand flute direction are standard for conventional and climb milling setups.

This end mill is suited for roughing applications in job shops, maintenance machining, and production environments. It excels in slotting, peripheral milling, and pocket roughing where maximizing metal removal rate matters more than surface finish. The regular length profile makes it practical for setups with limited spindle-to-work clearance. It is not centercutting, so plunge milling is not recommended without a pilot hole or ramping entry. Machinists and tool-and-die professionals working in steel, alloy steel, cast iron, and similar materials will find this a reliable roughing tool.

Key Features

• M42 cobalt HSS construction for elevated heat and wear resistance compared to standard M2 HSS
• 4-flute roughing geometry for high chip load and efficient material removal
• Bright, uncoated finish suitable for dry or flood-coolant roughing cuts
• 3/8 inch shank matches 3/8 inch cutting diameter for direct collet or end mill holder mounting
• Right-hand cut and right-hand helix for conventional spindle-direction compatibility
• Single-end design with regular overall length for general-purpose roughing setups

Compatibility

Designed as a standard-shank roughing end mill compatible with 3/8 inch collets, end mill holders, and Weldon-flat holders on vertical milling machines and CNC machining centers.

Installation Notes

Installation is performed by machinists following standard toolholding procedures. Power down and lock out the machine spindle before changing tooling. Ensure the shank is fully seated and clamped to the manufacturer-specified engagement depth for the holder type in use. Because this tool is not centercutting, avoid direct axial plunge entry; use a ramping or helical entry strategy when entering closed pockets.