Hertel 91197012 Roughing End Mill 3/8 in 4 Flute Cobalt

Product Description

The HERTEL 91197012 is a single-end roughing end mill designed for aggressive material removal in milling applications. Built from M42 cobalt high-speed steel with a Titanium Nitride (TiN) coating, this tool handles tough ferrous materials and interrupted cuts where standard HSS tooling falls short. The 3/8 inch diameter cutter features 4 right-hand flutes with a fine pitch geometry that breaks chips into smaller segments, reducing cutting forces and heat buildup during heavy roughing passes. With a 3/4 inch length of cut and 2.5 inch overall length, it fits standard end mill holders and collet chucks used on knee mills, CNC machining centers, and manual bridgeport-style machines.

This roughing end mill is suited for production and job shop environments where fast stock removal on steel, stainless, cast iron, and high-temperature alloys is required. The centercutting design allows plunge entry into the workpiece without a pre-drilled hole, supporting both ramp and direct plunge operations. The TiN coating extends tool life by reducing friction and resisting wear at elevated surface speeds. It is installed by machinists and tool and die professionals in both manual and CNC milling setups.

Key Features

• M42 cobalt HSS construction for improved hot hardness and wear resistance over standard M2 HSS
• Titanium Nitride (TiN) coating reduces friction and extends tool life in ferrous materials
• Fine pitch, 4-flute roughing geometry breaks chips into short segments for efficient evacuation
• Centercutting capable — supports direct plunge and ramp entry operations
• Right-hand cut and right-hand flute direction for use with standard spindle rotation
• 3/8 inch shank diameter matches cutter diameter for direct collet or end mill holder mounting

Compatibility

Designed as an OEM-style replacement or standard tooling option for any milling machine accepting a 3/8 inch shank end mill, including knee mills, manual bridgeports, and CNC vertical machining centers with compatible collet chucks or end mill holders.

Installation Notes

Installation and tool changes must be performed with the machine spindle fully stopped and power isolated. Seat the shank fully into the holder before torquing the retention screw or collet nut to prevent pullout under cutting load. Tool runout should be checked with a dial indicator after mounting, as excessive runout accelerates wear and degrades surface finish. Handle TiN-coated tooling carefully to avoid nicking the cutting edges during storage and setup.