Square End Mills
When your workpiece is a block of hardened tool steel or a heat-treated component (HRC50-70), you're not just cutting metal—you're battling extreme temperatures, immense cutting forces, and severe abrasive wear. Using a standard end mill in these conditions leads to rapid tool failure, dimensional inaccuracy, and lost productivity.
The JUN-YI series of square end mills for high-hardness machining is engineered to conquer these extreme conditions. We have systematically enhanced the three pillars of tool performance: substrate, coating, and geometry. The result is a cutting tool that delivers unwavering stability, precision, and tool life, allowing you to machine the hardest materials with confidence.
The JUN-YI Advantage in Hard Milling:
- Premium Carbide Substrate: We begin with a specialized grade of ultra-fine micrograin carbide. This provides the fundamental toughness and heat resistance required to prevent the cutting edge from fracturing under the intense stress of hard milling.
- Advanced High-Temperature Coatings: Each tool is protected by a state-of-the-art nanocomposite coating (e.g., AlTiN, TiSiN). This layer possesses exceptional hot hardness and thermal stability, acting as a barrier that allows for aggressive high-speed dry machining while drastically reducing wear.
- Robust Cutting Geometry: Featuring a reinforced core for maximum rigidity, optimized helix angles, and critical cutting-edge preparation (honing), our design creates a strong, impact-resistant edge that slices cleanly and resists chipping, which is the key to reliable performance.
Our comprehensive product matrix is designed to provide the perfect tool for any task. Use this guide to select the ideal end mill for your application:
- For Slotting & Aggressive Roughing
- 2-Flute Square End Mills (35°):
- Profile: Offers the largest flute valley for maximum chip evacuation. This is essential for preventing chip packing and recutting when performing deep slotting operations.
- Best For: Creating grooves and roughing out pockets in hardened materials.
- For Side Milling & General Finishing
- 4-Flute Square End Mills (35°):
- Profile: The industry standard for a balance of strength and performance. Compared to 2-flutes, the 4-flute design allows for higher feed rates in stable side milling, yielding better productivity and surface finish.
- Best For: Finishing walls, profiling, and general-purpose contouring.
- For High-Efficiency Finishing
- 6-Flute / 8-Flute Square End Mills:
- Profile: Engineered for high-speed finishing. The increased number of flutes allows for a dramatic increase in feed rate with a shallow depth of cut, resulting in a superior surface finish in a fraction of the time.
- Best For: Mirror finishing, 3D surface finishing, and high-speed trochoidal milling.
- For Deep Cavity & Complex Geometry Machining
- Long Flute Series: Designed with an extended cutting length to machine tall walls and deep profiles in a single pass.
- Long Shank Series: Provides extra overall length to reach deep into pockets and cavities, ensuring the tool holder and spindle clear the workpiece.
- Long Neck Series: This specialized "short-flute, long-neck" design is a game-changer for complex 3D contouring. The short, rigid cutting edge minimizes vibration and deflection, while the slim neck provides clearance to reach into tight corners and past part features.
We offer a full range of extended-reach solutions for your most challenging parts:
Don't let hardened materials dictate your production schedule. Take control with a tooling solution that's as tough as the materials you cut.
Explore our complete product listings, or contact our engineering team today for a personalized tooling strategy for your most demanding applications.
