12mm 4-Flute R2mm 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.

R2mmD1 12mmL2 45mmD2 12mmOAL 100mm4 FlutesnACoHRC65Standard ReachMOQ 1 pc

Get Pricing & Stock

Reference price

$124.52

Ref. factory price (USD)

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

nACo · 4 Flute · HRC65

12mm 4F R2mm nACo

L2 45mm · D2 12mm · OAL 100mm

Standard Reach · HRC65

✓ Factory direct pricing

✓ MOQ 1 piece, ships 1–5 days

✓ Custom radius in 0.1mm increments

Technical Specifications

Corner Radius2 mm
Cutter Diameter (D1 h7)12 mm
Flute Length (L2)45 mm
Shank Diameter (D2 h6)12 mm
Overall Length (L1)100 mm
Number of Flutes4
End GeometryCorner Radius (Bull Nose)
CoatingnACo Nano-AlCrN composite
Max Material HardnessHRC65
Reach CategoryStandard (L1/D1 = 8.3×)
Helix Angle30°–35°
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 · 4 Flute · HRC65 · R2mm

12mm 4-flute R2mm nACo corner radius end mill — L2=45mm OAL=100mm
Corner R
2mm
D1 h7
12mm
L2
45mm
D2 h6
12mm
L1
100mm
Reach
Standard

Heavy-corner fillet for energy, marine, and structural components

  • Produces R2mm fillets without interpolation — direct plunge-to-shoulder possible
  • Widely used in wind turbine nacelle components and frame pockets
  • Reduces stress concentration on R2mm structural fillets vs machined-in ball nose
  • Long-reach variants for deep pocket access (L1 up to 150mm)
Radius Selection Tip: R2mm at this tool diameter means a significant portion of the cutting edge is curved. In HRC65 steel, reduce feed rate 10–15% vs R1mm to maintain consistent chip load across the radius. Trochoidal milling strategies work well for R2mm pocketing.

12mm nACo — Where This Tool Fits

  • Large mould and die shoulder milling
  • Structural bracket and frame pocketing
  • Transmission case features
  • Wind turbine blade mould profiling
Machining Tip: ø12mm in HRC65 steel: use 0.5×D DOC for first passes to verify fixturing, then increase to 1×D for production. Corner radius is especially beneficial at this size where vibration-induced corner micro-chipping is common in hardened steel.

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
ISO HISO PnACo corner radius end mill HRC654 flute bull nose end mill hardened steelcorner radius carbide end mill hard millingradius end mill die steel HRC65

ø12mm R2mm nACo · 4 Flute · HRC65 — Other Flute Lengths

nACo · 4 Flute · HRC65 — Other Corner Radii at ø12mm

ø12mm R2mm / L2 45mm — Other Variants

Order 12mm R2mm 4-Flute nACo Today

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