Hertel E299921161 Square End Mill 17/64 in 4 Flute Cobalt

Product Description

The HERTEL E299921161 is a single-end, square-profile cobalt end mill designed for milling ferrous and hard materials in machining centers and manual mills. Built from M42 cobalt high-speed steel, it delivers improved heat and wear resistance compared to standard M2 HSS tooling. The cutter measures 17/64 inches (0.2656 inches) in diameter with a 3/4-inch length of cut and a 2-1/2-inch overall length. A 30-degree right-hand spiral helix and four flutes provide efficient chip evacuation and a smooth cutting action. The bright, uncoated finish suits general-purpose applications where coating is not required. Machinists and tool-and-die professionals typically specify this geometry for profiling, slotting, and peripheral milling operations.

This end mill is suited for use in production and job-shop environments handling low-alloy steels, stainless steels, cast iron, and similar workpiece materials. The 3/8-inch shank diameter fits standard ER collet chucks, end-mill holders, and Weldon-style tool holders common in vertical machining centers and knee mills. Center-cutting geometry allows direct plunge entry without pre-drilling. The right-hand cutting direction is standard for conventional and climb milling on CNC and manual equipment.

Key Features

• M42 cobalt HSS construction for improved hardness and heat resistance over standard HSS grades
• 4-flute, right-hand spiral design for smooth chip flow in ferrous and difficult-to-machine materials
• Center-cutting capable — supports direct plunge milling without a pilot hole
• 30-degree helix angle balances cutting force and surface finish across a range of materials
• Bright/uncoated finish suitable for general-purpose and re-sharpenable tooling applications
• Single-end configuration with 3/8-inch shank for broad holder compatibility

Compatibility

Designed as an OEM-style replacement or standard tooling selection for machining setups requiring a 3/8-inch shank, 17/64-inch diameter square end mill in cobalt HSS.

Installation Notes

Installation is performed by qualified machinists following shop safety procedures. The machine spindle must be fully stopped and locked out before loading or removing the tool from its holder. Ensure the shank is fully seated and the collet or set screw is torqued per the tool-holder manufacturer's specification. Verify runout with a dial indicator before beginning a production cut to avoid premature tool wear or workpiece damage.