Hertel 91197251 Roughing End Mill 1-1/4 in 6 Flute Cobalt

Product Description

The HERTEL 91197251 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 workpiece materials where heat resistance matters. It features a 1.25-inch mill diameter, 6 fine-pitch flutes, and a 6-inch length of cut, delivering the chip clearance and edge strength needed for hogging cuts in production and job-shop environments. Right-hand cutting and right-hand flute direction are standard. Machinists and tool-and-die professionals are the primary users of this tool class.

This roughing end mill is suited for manual and CNC milling applications in industrial, production, and maintenance machining settings. The fine-pitch, 6-flute geometry reduces chatter and improves surface finish on roughing passes compared to coarser-pitch designs. The 1.25-inch shank diameter matches the mill diameter for direct collet or end-mill-holder mounting without a reducer. It is not center-cutting, so it is not suited for plunge operations without a pre-drilled entry point. No extended reach or variable helix features are present.

Key Features

• M42 cobalt HSS construction for improved heat and wear resistance over standard M2 HSS
• 6 fine-pitch flutes for reduced vibration and improved chip evacuation on roughing passes
• 1.25-inch mill diameter and 1.25-inch shank diameter — no reducer required for standard holders
• 6-inch length of cut for deep-cavity and deep-shoulder milling applications
• Right-hand cut, right-hand helix — standard orientation for conventional CNC and manual mills
• Bright, uncoated finish suitable for use with or without cutting fluid

Compatibility

Designed for use in standard end-mill holders, collet chucks, and Weldon-style holders accepting a 1.25-inch shank diameter. Confirm holder runout and clamping torque specifications per the holder manufacturer before use.

Installation Notes

Installation and tool changes must be performed with the machine spindle fully stopped and locked out per applicable safety procedures. Secure the shank with the appropriate end-mill holder or collet and verify tool runout before beginning a cut. Because this tool is not center-cutting, always establish an entry point by drilling or ramping before engaging a full-width plunge. Inspect cutting edges for chipping or wear between operations, as cobalt tooling can be brittle under intermittent heavy impacts.