4-Flute · nACo · R0.3mm · HRC65 · Standard Reach
2mm 4-Flute R0.3mm nACo Solid Carbide Corner Radius End Millfor HRC65 Hardened Steel
nACo (nano-AlCrN composite) corner radius end mills deliver the highest performance tier for hard milling in die steel, tool steel, and hardened components up to HRC65. The corner radius geometry is especially critical at high hardness — it eliminates the notching failure mode that destroys sharp-corner tools in hardened steel. Combined with nACo's 3,800 HV hardness and 1,100°C oxidation resistance, this tool enables dry semi-finish and finish passes in H13, P20, D2, and S7 mould steel directly after heat treatment.
Get Pricing & Stock
Reference price
$7.87
Ref. factory price (USD)
Based on rod stock cost as of 2026-03-31. Final quotation may differ.

2mm 4F R0.3mm nACo
L2 6mm · D2 4mm · OAL 50mm
Standard Reach · HRC65
✓ Factory direct pricing
✓ MOQ 1 piece, ships 1–5 days
✓ Custom radius in 0.1mm increments
Full Dimensions
Technical Specifications
| Corner Radius | 0.3 mm |
| Cutter Diameter (D1 h7) | 2 mm |
| Flute Length (L2) | 6 mm |
| Shank Diameter (D2 h6) | 4 mm |
| Overall Length (L1) | 50 mm |
| Number of Flutes | 4 |
| End Geometry | Corner Radius (Bull Nose) |
| Coating | nACo Nano-AlCrN composite |
| Max Material Hardness | HRC65 |
| Reach Category | Standard (L1/D1 = 25.0×) |
| Helix Angle | 30°–35° |
| 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 · 4 Flute · HRC65 · R0.3mm

R0.3mm Corner Geometry
Light edge protection for tight-tolerance pocket corners
- ▸Prevents corner micro-fracture in interrupted cuts
- ▸Works within tight pocket radius tolerances (e.g. R0.3 ± 0.05mm)
- ▸Preferred radius for watch and instrument component pockets
- ▸Usable on features requiring clean corner breaks in cast iron
ø2mm Applications
2mm nACo — Where This Tool Fits
- ▸Precision instrument and watch component features
- ▸Medical device micro-pocket machining
- ▸Die insert fine detail features
- ▸Electronic connector pocket profiling
Coating Performance
nACo on Corner Radius Geometry
- ▸nACo hardness > 3,800 HV — critical for corner edge stability in HRC65 steel
- ▸Oxidation to 1,100°C — supports dry cutting in deep die pockets
- ▸Corner radius + nACo eliminates notching failure common in hard milling
- ▸Enables direct finish after heat treatment — skip grinding on mould steel
Same ø2mm Diameter, Other Radii
nACo · 4 Flute · HRC65 — Other Corner Radii at ø2mm
Same Dimensions, Other Coatings
ø2mm R0.3mm / L2 6mm — Other Variants
Order 2mm R0.3mm 4-Flute nACo Today
Factory direct. MOQ 1 piece. Pricing confirmed within 4 hours.

