CNC grinding: end mills, drills & special cutters
See how we use a CNC grinder to make carbide end mills, drills and special cutters.
Watch on YouTube2-Flute · nACo · R7mm Ball · HRC65 · Standard Reach
14mm 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.
R7mm BallD1 14mmL2 45mmD2 14mmOAL 100mm2 FlutesnACoHRC65Standard ReachMOQ 1 pc
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Reference price
$149.88
Ref. factory price (USD)
Based on rod stock cost as of 2026-05-06. Final quotation may differ.
R7mm 2F nACo Ball Nose EM
L2 45mm · D2 14mm · OAL 100mm
Standard Reach · HRC65
✓ Factory direct pricing
✓ MOQ 1 piece, ships 1–5 days
✓ Custom ball radii available
Full Dimensions
Technical Specifications
| Ball Radius (R) | 7 mm |
| Cutter Diameter (D1 h7) | 14 mm |
| Flute Length (L2) | 45 mm |
| Shank Diameter (D2 h6) | 14 mm |
| Overall Length (L1) | 100 mm |
| Number of Flutes | 2 |
| End Geometry | Ball Nose (Spherical) |
| Coating | nACo Nano-AlCrN composite |
| Max Material Hardness | HRC65 |
| Reach Category | Standard (D2/L1 = 0.140) |
| Substrate | K10/K20 Ultra-Fine Grain Carbide |
| Shank Tolerance | h6 |
| MOQ | 1 piece |
| Lead Time (standard) | 1–5 business days |
| Lead Time (custom) | 5–15 business days |
nACo · 2 Flute · HRC65
Ball R
7mm
D1 h7
14mm
L2
45mm
D2 h6
14mm
L1
100mm
Reach
Standard
Where This Tool Excels
R7mm 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: R7mm 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.
3D Finishing Reference
Scallop Height vs Step-Over — R7mm
Residual scallop height (cusps) between adjacent tool paths, calculated for R7mm ball nose:
| Step-Over | Step-Over mm | Scallop Height (µm) | Typical Ra (µm) |
|---|---|---|---|
| 2% D1 | 0.28 | 1.4 | ≈ 0.28 |
| 5% D1 | 0.70 | 8.8 | ≈ 1.75 |
| 8% D1 | 1.12 | 22.4 | ≈ 4.49 |
| 10% D1 | 1.40 | 35.1 | ≈ 7.02 |
| 15% D1 | 2.10 | 79.2 | ≈ 15.84 |
| 20% D1 | 2.80 | 141.4 | ≈ 28.29 |
h = R − √(R² − (ae/2)²). Actual Ra depends on feed rate, chip load, and material.
ISO HISO P
Coating Performance
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
Related Ball Nose Variants
Same Size in Other Coatings
Same Ball Radius, Different Reach
R7mm nACo · 2 Flute · HRC65 — Other Flute Lengths
Order R7mm 2-Flute nACo Ball Nose Today
Factory direct. MOQ 1 piece. Pricing confirmed within 4 hours.
FROM OUR WORKSHOP
Watch us grind and inspect our tools
Two videos filmed in our workshop: CNC tool grinding and dimensional inspection.
Measuring carbide end mills at 0.001 mm
Watch our ZOLLER inspection process for precision carbide end mills.
Watch on YouTube