Long Reach Corner Radius Carbide End Mill

What Is a Long Reach Corner Radius Carbide End Mill?

An extended neck corner radius end mill combines an elongated neck, a reduced shank, and a precision corner radius to solve deep cavity machining challenges. By optimizing the reach-to-diameter ratio without sacrificing rigidity, it serves as the ultimate deep cavity milling end mill for aerospace and mold-making applications. The radiused edge—often called a reduced shank bull nose end mill—distributes cutting stress to prevent premature chipping, which is vital when machining hardened steel at 45HRC. Its slim neck geometry clears workpiece walls seamlessly, outperforming standard long reach end mills in extreme depths. Explore our complete solid carbide corner radius end mills collection.

Extra Long Reach Corner Radius Carbide End Mill Product Details

• Shank Dia (mm)：6mm 8mm 10mm 12mm 14mm 16mm
• Flute Dia.(mm)：6mm – 16mm
• Cutting Length (mm)：16mm – 45mm
• Overall Length (mm)：75mm – 150mm
• Flutes：4 Flutes
• HRC：HRC 45 / 50
• MOQ：1 pcs (standard) / 1-50 pc (custom)
• Quality Standards: DIN 6537 and DIN 6535-HA

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Solid Carbide Corner Radius End Mill Products Pictures

4 Flute Long Reach Corner Radius Carbide End Mill Size:

All dimensions in mm

Applicability for Materials

◎ = Perfect for    ○ = Suit    — = N/A

Key Technical Features and Cutting Specifications

TiAlN Coating, Helix Angle, and ISO Tolerance

This TiAlN coated long neck end mill series is engineered with a helix angle exceeding 35°, which promotes efficient chip evacuation in deep slot and cavity operations, reduces axial cutting force, and delivers improved surface finish on both roughing and semi-finishing passes. The TiAlN (Titanium Aluminum Nitride) coating provides high-temperature oxidation resistance up to approximately 900°C — a critical performance advantage when dry-machining alloy steel or pre-hardened tool steel. For extended-reach configurations, see our corner radius long shank end mills.

Application Range — Materials, Industries, and Machining Operations

Compatible Workpiece Materials

As a highly optimized mold making long reach end mill, this tool is designed for the following primary workpiece materials:

• Carbon steel — general structural and mechanical grades
• Alloy steel — chromium-molybdenum and nickel-chromium grades
• Pre-hardened and hardened steel up to 45HRC — including P20, H13, and NAK80
• Cast iron and nodular (ductile) cast iron — gray iron and GGG-40/GGG-60 grades

Industry Application Matrix

Selection Guide — How to Choose the Right Tool

Selecting the correct tool requires balancing reach length, corner radius value, number of flutes, and coating. For a broader decision framework, refer to our guide on how to choose carbide end mill types for your specific operation.

Key Selection Rules

• At reach ratios above 6×D, reduce axial depth of cut (ap) to no more than 0.05×D per finishing pass.
• When selecting a 4 flute long reach corner radius end mill for hardened steel finishing, ensure the helix angle is >35° to manage cutting forces effectively. For standard-length options, see our 4 flute end mill guide.
• For a solid carbide micro long reach end mill (D ≤ 3 mm), reduce feed rate by 20–30% versus catalog values when machining hardened steel to prevent breakage.

Purchasing Checklist — What Procurement Managers Must Confirm

A comprehensive carbide end mill selection process should always include these checkpoints:

1. Verify actual workpiece hardness (HRC) — not the nominal material grade. When you specifically need a corner radius end mill for 45HRC, ensure your P20 material isn’t actually testing at 48HRC in practice.
2. Specify the exact corner radius value — R0.2, R0.3, R0.5, R1.0, etc. Ordering without the R-value results in production delays.
3. Request tolerance documentation — confirm diameter tolerance matches your tool holder system (0/−0.020 for D≤12mm).

Ready to machine deeper, cleaner, and longer without tool breakage or dimensional rejects? Our tools are in stock and ship fast. Send us your drawing, workpiece material, and target hardness — and our CNC applications team will confirm the right tool within 24 hours. Contact us by WhatsApp or email for a fast quote and complimentary tool selection consultation.

Failure Cases — Common Errors and How to Avoid Them

Improving carbide tool life starts with diagnosing the root cause before it costs you a workpiece.

Case 1: Corner Chipping on Hardened Steel at 45HRC

A mold shop ran a standard carbide end mill with a 30° helix on P20 steel hardened to 44HRC. The corner radius chipped catastrophically. Root cause: a helix angle below 35° generates elevated radial cutting force at the corner tip. Switching to our >35° helix tool resolved the issue immediately.

Case 2: Vibration and Surface Finish Failure

An aerospace subcontractor used a 6mm diameter long reach end mill at 6×D reach while keeping spindle speed identical to a standard-length tool. The result: visible chatter marks. Corrective action: reduce ap to 0.3mm, cut RPM by 25%, and switch exclusively to climb milling. This precise parameter adjustment effectively transforms the tool’s performance into that of an anti-vibration long reach end mill.

Corner Radius Carbide End Mill Cutter Packaging & Delivery