Corner Radius End Mills

When machining hardened steels above HRC50, the most common point of failure for a square end mill is its sharp, 90-degree corner. The slightest chip at this critical point compromises dimensional accuracy, ruins surface finish, and drastically shortens tool life.

The JUN-YI series of Corner Radius End Mills is the definitive engineering solution to this core problem. By incorporating a small, precise radius on the tool's corner, we reinforce the cutting edge where it's most vulnerable. This simple but critical feature distributes cutting forces, prevents chipping, and is the key to achieving stable, predictable, and long-lasting performance in the most demanding hard milling applications.

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Why Choose JUN-YI's Corner Radius End Mills?

  • The Power of the Corner Radius:
    The corner radius acts as a structural reinforcement, effectively dissipating the stress concentrations that cause sharp corners to fail.1 This directly translates to significantly longer tool life and a more robust, reliable machining process.

  • Premium Substrate and Coating：
    We use a specialized grade of ultra-fine micrograin carbide combined with advanced, high-temperature AlTiN / TiSiN nanocomposite coatings. This powerful combination ensures the tool maintains its hardness and wear resistance even in the extreme heat of high-speed dry machining.

  • Robust Overall Geometry：
    Beyond the corner radius, each tool features a reinforced core for maximum rigidity and precision-honed cutting edges. This creates a tool that is strong and stable from tip to shank, ready to handle the intense pressures of hard milling.

Select the optimal tool for your specific machining needs from our comprehensive lineup:

For Slotting & Roughing Applications

  • 2-Flute Corner Radius End Mills (35°):
    • Profile: Offers maximum space for chip evacuation, making it the top choice for slotting and aggressive pocketing in hardened materials. The corner radius provides the necessary edge strength to withstand these high-load operations without failure.
    • Best For: Machining grooves and roughing out cavities in hardened steels.

For Side Milling & Finishing Applications

  • 4-Flute Corner Radius End Mills (35°):
    • Profile: The higher flute count provides excellent stability and allows for increased feed rates, resulting in superior surface quality and efficiency. It is the ideal solution for finishing passes and profiling.
    • Best For: Finishing mold walls, contour machining, and applications where both precision and productivity are critical.

For Deep Cavity & Extended Reach Machining

  • Long Shank Series:
    • Profile: Both our 2-flute and 4-flute configurations are available in Long Shank versions. When you need to machine features deep inside a cavity, the extended shank provides the necessary clearance to prevent interference with the tool holder.

Stop letting corner failure dictate your tool changes and compromise your part quality. Choose a smarter, more durable hard milling strategy with JUN-YI.

To find the best solution for your most difficult machining problems, look through our comprehensive listings of custom endmills or contact our technical team right now!