Hertel 44839371 Roughing End Mill 3/4 in 4 Flute Cobalt

Product Description

The HERTEL 44839371 is a single-end cobalt roughing end mill designed for aggressive material removal in milling applications. Built from M42 cobalt high-speed steel with a bright, uncoated finish, it handles tough ferrous metals and heat-resistant alloys where standard HSS tooling falls short. The 3/4 inch cutting diameter paired with a coarse-pitch, 4-flute geometry breaks chips efficiently and reduces cutting forces, making it well-suited for heavy roughing passes. With a 2.5 inch length of cut and 4.75 inch overall length, it provides adequate reach for most standard milling setups without sacrificing rigidity.

This roughing end mill is intended for use in vertical and horizontal milling machines, CNC machining centers, and manual mills where rapid stock removal is the priority. It is a right-hand cutting, right-hand flute tool, which means it runs with conventional spindle rotation. The 3/4 inch straight shank fits standard ER collet chucks, end mill holders, and side-lock holders of matching bore size. It is appropriate for job shops, tool rooms, and production environments machining steel, stainless, and similar work materials.

Key Features

• M42 cobalt construction for improved heat and wear resistance over standard M2 HSS
• Coarse-pitch flute geometry promotes chip clearance and reduces cutting load during roughing
• 4-flute single-end configuration balances material removal rate with tool stability
• Bright, uncoated finish suitable for use with cutting fluid in a range of ferrous materials
• Right-hand cut and right-hand flute direction compatible with standard milling machine spindles
• Non-center-cutting design — requires a pre-drilled or pre-milled entry point

Compatibility

Designed as a direct-fit replacement for 3/4 inch shank roughing end mill applications in standard ER collet chucks, Weldon-style side-lock holders, and end mill holders with a 3/4 inch bore.

Installation Notes

Installation should be performed by a qualified machinist or tooling technician. Ensure the spindle is fully stopped and the machine is powered down before changing tooling. Seat the shank fully into the holder to the minimum insertion depth recommended by the holder manufacturer, and confirm runout with a dial indicator before cutting. Because this tool is not center-cutting, do not plunge directly into solid material — use a pre-drilled hole or ramp entry.