15mm 2-Flute nACo Solid Carbide Ball Nose End Millfor HRC65 Hardened Steel 3D Contouring

nACo (nano-AlCrN composite) ball nose end mills represent the pinnacle of carbide ball-end tooling for hard milling. With coating hardness exceeding 3,800 HV and oxidation stability up to 1,100°C, nACo enables dry Z-level finishing in hardened mould steel (P20, H13, S7, D2) up to HRC65 — directly replacing the need for grinding after heat treatment. 2-flute geometry reduces vibration in long-reach configurations common in deep die cavities. Achieves Ra 0.4–0.8µm surface finish in HRC65 steel.

R7.5mm BallD1 15mmL2 45mmD2 16mmOAL 100mm2 FlutesnACoHRC65Standard ReachMOQ 1 pc

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Reference price

$217.81

Ref. factory price (USD)

Based on rod stock cost as of 2026-03-31. Final quotation may differ.

nACo · 2 Flute · HRC65

R7.5mm 2F nACo Ball Nose EM

L2 45mm · D2 16mm · OAL 100mm

Standard Reach · HRC65

✓ Factory direct pricing

✓ MOQ 1 piece, ships 1–5 days

✓ Custom ball radii available

Technical Specifications

Ball Radius (R)7.5 mm
Cutter Diameter (D1 h7)15 mm
Flute Length (L2)45 mm
Shank Diameter (D2 h6)16 mm
Overall Length (L1)100 mm
Number of Flutes2
End GeometryBall Nose (Spherical)
CoatingnACo Nano-AlCrN composite
Max Material HardnessHRC65
Reach CategoryStandard (L1/D1 = 6.7×)
SubstrateK10/K20 Ultra-Fine Grain Carbide
Shank Toleranceh6
MOQ1 piece
Lead Time (standard)1–5 business days
Lead Time (custom)5–15 business days

nACo · 2 Flute · HRC65

R7.5mm 2-flute nACo solid carbide ball nose end mill — L2=45mm OAL=100mm
Ball R
7.5mm
D1 h7
15mm
L2
45mm
D2 h6
16mm
L1
100mm
Reach
Standard

R7.5mm nACo 2F — Recommended Applications

  • Injection mould parting surface contouring
  • Wind turbine blade mould 3D finishing
  • Structural aerospace component contouring
  • Large forging die rough and semi-finish passes
Machining Tip: R7.5mm produces wide effective cutting zone. In HRC65 hardened steel, use 10–20% D1 step-over for semi-finish; this gives scallop < 0.05mm. At this diameter, ensure minimum wall thickness of 6mm for workholding rigidity, or use vibration-damping toolholder.

Scallop Height vs Step-Over — R7.5mm

Residual scallop height (cusps) between adjacent tool paths, calculated for R7.5mm ball nose:

Step-OverStep-Over mmScallop Height (µm)Typical Ra (µm)
2% D10.301.50.30
5% D10.759.41.88
8% D11.2024.04.81
10% D11.5037.67.52
15% D12.2584.916.97
20% D13.00151.530.31

h = R − √(R² − (ae/2)²). Actual Ra depends on feed rate, chip load, and material.

ISO HISO P

nACo — Why It Works for Ball-End Machining

  • nACo hardness > 3,800 HV — sustains edge sharpness in HRC65 steel
  • Oxidation stable to 1,100°C — enables dry hard milling
  • Eliminates grinding after heat treatment for mould steel
  • Achieves Ra 0.4–0.8µm in HRC65 P20/H13/S7/D2 steel
  • 2-flute reduces vibration in deep-cavity long-reach cuts

Same Size in Other Coatings

Order R7.5mm 2-Flute nACo Ball Nose Today

Factory direct. MOQ 1 piece. Pricing confirmed within 4 hours.