Hertel 91197426 Roughing End Mill 1-1/4 in 6 Flute Cobalt

Product Description

The HERTEL 91197426 is a single-end roughing end mill designed for aggressive material removal in milling applications. Built from M42 cobalt high-speed steel with a bright, uncoated finish, it delivers durability and heat resistance in demanding cutting environments. The 1.25-inch diameter cutter features 6 right-hand flutes in a fine-pitch configuration with a 4-inch length of cut and a 6.5-inch overall length. It is center-cutting and right-hand cutting, making it suitable for plunge and ramp entry. Machinists, tool-and-die workers, and CNC operators rely on this style of cutter for roughing passes on steel, alloy, and stainless workpieces before finishing operations.

This roughing end mill fits standard milling machines, machining centers, and CNC mills accepting a 1.25-inch straight shank. It is suited for roughing passes on ferrous metals and harder alloys where a standard high-speed steel end mill would wear prematurely. The fine-pitch, 6-flute geometry breaks chips efficiently and reduces chatter at high material removal rates. It is a single-end tool, meaning the cutting geometry is on one end only, and extended reach is not provided. Typical applications include production milling, prototype work, and heavy roughing in job shop and manufacturing environments.

Key Features

• M42 cobalt high-speed steel construction for improved heat and wear resistance over standard HSS
• 6 right-hand flutes in a fine-pitch arrangement for efficient chip evacuation during roughing
• Center-cutting design allows direct plunge entry without a pre-drilled hole
• 4-inch length of cut provides deep-pocket milling capability
• Bright, uncoated finish suitable for use with cutting fluids on a wide range of ferrous materials
• Right-hand cutting and right-hand flute direction, compatible with standard spindle rotation

Compatibility

Designed as an OEM-style single-end roughing end mill with a 1.25-inch straight shank, compatible with standard ER or end mill holders accepting 1.25-inch shank tooling on manual and CNC milling machines.

Installation Notes

Installation and tool changes must be performed by a qualified machinist with the spindle fully stopped and the machine powered down or in a locked-out state per OSHA lockout/tagout procedures. Secure the shank in a properly sized end mill holder or collet chuck and torque the retention hardware according to the toolholder manufacturer specifications. Inspect the cutter for chipping or wear before each use, as a damaged cutting edge can cause workpiece damage or tool breakage. Follow applicable shop safety standards and machine tool manufacturer guidelines for speeds, feeds, and coolant application.