Aluminium-CNC-Bearbeitung: vollständiger Leitfaden 2026
Ingenieur-Leitfaden zur CNC-Aluminiumbearbeitung: 6061 vs 7075 vs 2024, Bearbeitbarkeit, Eloxieren, Kosten, Lieferzeiten und Designtipps.
15 min read
Aluminium ist das Arbeitspferd der CNC-Bearbeitung — etwa 70 % der industriellen Arbeit von JLYPT läuft auf einer Aluminium-Sorte. Dieser Leitfaden ist die Tiefenanalyse: welche Legierung für welchen Job, welche Toleranzen sind realistisch, welche Veredelungen funktionieren.
Why aluminium dominates CNC
Aluminium hits a sweet spot of properties no other commodity material matches:
- Light — about 1/3 the density of steel (2.7 g/cm³ vs 7.85). Critical for aerospace, drones, robotics.
- Strong enough — 6061-T6 yields at 276 MPa, comparable to many mild steels.
- Cuts fast — soft enough to remove material at 3–5× the rate of stainless or titanium.
- Anodises beautifully — every colour, hard surface, integral to the part.
- Conducts heat — ideal for heat sinks, electronics enclosures, LED housings.
- Corrosion-resistant by default — the natural oxide layer protects without coating.
- Recyclable — chips and offcuts have real scrap value, lowering net cost.
Alloy comparison — which one and why
| Alloy | Yield (MPa) | Machinability | Anodise | Best for | Cost |
|---|---|---|---|---|---|
| 6061-T6 | 276 | Excellent (3-rated) | Yes — perfect | Default for 70% of work | 1.0× |
| 6063-T5 | 215 | Excellent | Yes — best cosmetic | Extruded profiles, decorative | 1.05× |
| 7075-T6 | 503 | Good (4-rated) | Acceptable, mottled | Aerospace, motorsport, structural | 1.4× |
| 7075-T651 | 503 | Good | Acceptable | Stress-relieved 7075 for stable parts | 1.5× |
| 2024-T351 | 345 | Good | Poor (clad recommended) | Aerospace skins, fatigue parts | 1.3× |
| 5052-H32 | 193 | Excellent | Yes | Marine, sheet-metal-style folded | 1.0× |
| 5083 | 215 | Good | Yes | Marine welded structures | 1.2× |
| MIC-6 / Cast tool | 170 | Excellent | Yes (cosmetic mediocre) | Vacuum chucks, optical bases, jigs | 1.6× |
| A380 die-cast | 160 | Tricky (porosity) | Difficult | Cast housings (cnc finishing only) | 0.9× |
When 6061 is the right choice
- General-purpose brackets, housings, plates.
- Anything that needs cosmetic anodising.
- Cost-sensitive work where strength is moderate.
- Welded assemblies (6061 welds well).
When 7075 is worth the upgrade
- Structural aerospace components (wing ribs, frames).
- High-stress brackets that fail in 6061 testing.
- Motorsport (fewer parts means weight matters more).
- Where 80%+ more strength justifies the 40% cost.
Machinability and cycle times
Aluminium machines fast — but how fast depends on alloy choice and tooling. Indicative cycle times for a representative 50×50×25 mm bracket with moderate complexity:
| Alloy | Roughing speed | Finishing speed | Tool life | Total cycle (typical) |
|---|---|---|---|---|
| 6061-T6 | Very fast | Very fast | Long | 8 min |
| 7075-T6 | Fast | Fast | Medium | 11 min |
| 2024 | Fast | Fast | Medium | 12 min |
| MIC-6 (cast tool plate) | Fast | Excellent | Long | 9 min |
| Stainless 316L (compare) | Slow | Slow | Short | 38 min |
Achievable tolerances on aluminium
| Feature | Standard CNC | Precision CNC | High-end (with care) |
|---|---|---|---|
| External dimensions | ±0.10 mm | ±0.025 mm | ±0.005 mm |
| Hole diameter (drilled) | ±0.05 mm | ±0.013 mm | ±0.005 mm |
| Hole diameter (reamed) | ±0.013 mm | ±0.005 mm | ±0.0025 mm |
| Surface finish (Ra) | 3.2 µm | 0.8 µm | 0.4 µm |
| Flatness (over 100 mm) | 0.05 mm | 0.013 mm | 0.005 mm |
| Concentricity / true position | 0.05 mm | 0.025 mm | 0.013 mm |
Aluminium's thermal expansion (~23 ppm/°C) is roughly twice that of steel — so for ±0.005 mm tolerances on parts longer than 100 mm, JLYPT machines in a temperature-controlled cell. See our tolerances and GD&T guide for more.
Finishes that work on aluminium
Common — fast, cheap
- As-machined + deburr — bare metal, lowest cost.
- Bead blast — uniform matte texture, hides tool marks.
- Type II anodise (decorative) — clear, black, blue, red, gold etc.
- Brush finish — directional grain like appliance steel.
Premium — performance
- Type III hard anodise — 60 HRC surface, wear resistance.
- Chromate conversion (Alodine) — corrosion + paint primer.
- Powder coat — thick, durable, any colour.
- Electroless nickel plate — wear + uniform thickness.
Industry applications
- Consumer electronics — laptop chassis, phone frames, camera bodies. 6061 + Type II anodise dominates.
- UAV and drones — frames, motor mounts, gimbals. 7075 for structural, 6061 for non-critical. See UAV parts.
- Aerospace — brackets, instrumentation housings, ground support. 7075 + 2024 dominate. See aerospace manufacturing.
- Robotics — joint housings, drive arms, gripper bodies. 6061 + hard anodise common. See robotic parts.
- Heat sinks & LED housings — 6061 or 6063 for thermal conductivity, anodised black for emissivity.
- Optical & imaging — MIC-6 cast tool plate for dimensional stability over time.
- Automotive prototypes — 7075 for race-car components, 6061 for OEM-grade prototypes.
Real cost ranges
Indicative pricing for a typical 50×50×25 mm aluminium bracket, anodised type II, batch quantities:
| Quantity | 6061 unit cost | 7075 unit cost | Per-unit drop |
|---|---|---|---|
| 1 (prototype) | $95 | $130 | — |
| 10 | $28 | $42 | −71% |
| 100 | $11 | $18 | −61% |
| 1000 | $6.20 | $10 | −43% |
Want to lower your aluminium part cost without redesigning? See our cost reduction guide — typical savings: 20–40% by relaxing tolerances, switching from 7075 to 6061 where possible, and consolidating setups.
Design tips that save money on aluminium
- Internal corner radii ≥ 1 mm — lets us use larger, faster end mills.
- Wall thickness ≥ 0.8 mm — thinner walls deflect during cutting.
- Use 6061 unless you have a strength reason to upgrade — saves 30–40% on material + machining.
- Specify Type II anodise unless hardness is required — Type III roughly doubles finish cost.
- Don't demand mirror polish on cosmetic surfaces — bead blasting before anodising looks great and costs less.
- Tolerance only critical features — use ISO 2768-mK default for non-mating dimensions.
- Add 0.3 mm chamfers to all external edges — eliminates manual deburring labour.
- Avoid pockets deeper than 4× tool diameter — deep pockets need slow finishing passes.
Häufig gestellte Fragen
- 6061-T6 mit großem Abstand — etwa 70 % der CNC-Aluminiumarbeit verwendet sie. Wechseln Sie zu 7075 nur, wenn Festigkeitstests es erfordern.
- Ja, aber kosmetische Ergebnisse sind merklich schlechter — leicht fleckige oder ungleichmäßige Farbe.
- ±0,005 mm sind auf Produktionsausrüstung mit Sorgfalt erreichbar. Standardarbeit hält ±0,025 mm leicht.
- Ja — selbst nacktes Aluminium bildet eine selbstheilende Oxidschicht. Für aggressive Umgebungen (Marine) bietet Eloxieren erheblichen Schutz.
- 6061 und 5052 lassen sich gut schweißen (TIG). 7075 ist praktisch nicht schweißbar — verliert 50%+ Festigkeit am Schweißpunkt.
- Material: 7075 ist ~40 % teurer. Bearbeitung: ~25 % langsamer. Netto-Gesamtkosten: 7075-Teile kosten ~50 % mehr als 6061.
- Ja — wir lagern MIC-6 in gängigen Stärken. Standard für Vakuumspannfutter und Optikbasen.
- Aluminium gewinnt bei Festigkeit, Wärmeleitfähigkeit und Haltbarkeit. Kunststoffe gewinnen bei Gewicht und Isolierung.
Welche ist die häufigste Aluminiumlegierung für CNC?
Kann ich 7075 wie 6061 eloxieren?
Wie eng können Toleranzen auf Aluminium sein?
Ist Aluminium für den Außenbereich geeignet?
Können Sie bearbeitete Aluminiumteile schweißen?
Was ist der Kostenunterschied zwischen 6061 und 7075?
Kann JLYPT MIC-6 Werkzeugplatte beschaffen?
Wie vergleicht sich Aluminium mit Kunststoff-CNC-Teilen?
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Über den Autor
JLYPT Engineering Team
Senior CNC Application Engineers
Our application engineering team brings 15+ years of combined experience producing precision components for aerospace, medical, robotics and industrial automation customers.
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