Aluminum CNC Machining
Key takeaways
- Aluminum is the most popular CNC machining metal — lightweight, corrosion-resistant, and it machines 3–4× faster than steel.
- 6061 is the best all-round alloy; 7075 for high strength; 5052 for corrosion resistance and forming.
- Aluminum anodizes well (clear, color, and hard Type III) and supports tolerances down to ±0.01 mm.
- Get an exact price with an instant quote from your CAD file.
Aluminum CNC machining is the go-to choice for the majority of custom machined parts. Aluminum is lightweight (about one-third the weight of steel), corrosion-resistant, easy to machine, and recyclable — with an excellent strength-to-weight ratio. This guide covers the most common aluminum alloys, their properties, finishes, achievable tolerances, and typical applications.
Aluminum alloys we machine
| Alloy | Key properties | Best for |
|---|---|---|
| 6061 | Versatile, good strength, weldable, corrosion-resistant, anodizes well | General parts, brackets, housings, prototypes |
| 7075 | Very high strength (aircraft grade), lower corrosion resistance | Structural, aerospace, high-stress parts |
| 5052 | Excellent corrosion resistance, very formable (non-heat-treatable) | Enclosures, marine, sheet parts |
| 6063 | Good surface finish, extrudable, moderate strength | Architectural, trim, profiles |
| 2024 | High strength, good fatigue resistance | Aerospace structural components |
| MIC-6 | Cast plate, flat and dimensionally stable, low internal stress | Tooling plates, jigs, fixtures |
Properties of aluminum for machining
- Lightweight — ~2.7 g/cm³, about a third the weight of steel
- Excellent machinability — fast cutting speeds, long tool life, clean finishes
- Corrosion resistant — forms a protective oxide layer; anodizing improves it further
- Good thermal and electrical conductivity
- Recyclable and cost-effective
Surface finishes for aluminum parts
Aluminum accepts a wide range of finishes: as-machined, bead blasting, clear and color anodizing (Type II), hard anodizing (Type III) for wear resistance, brushing, polishing, powder coating, and chromate (Alodine).
Tolerances
Standard tolerance is ISO 2768-m (±0.1 mm); with precision machining we hold critical features to ±0.01 mm. Aluminum's machinability makes tight tolerances and fine finishes achievable and economical.
Applications
Automotive and motorsport, aerospace, electronics enclosures and heat sinks, robotics, consumer products, lighting, and industrial automation.
Machining tips
- 6061 is the best starting point unless you need 7075's strength or 5052's corrosion resistance.
- Specify the finish early — anodizing color and type affect appearance and lead time.
- Watch thin-wall deflection on lightweight parts; add fillets where possible.
Frequently asked questions
What is the best aluminum alloy for CNC machining?
6061 is the most versatile and widely used. Choose 7075 for maximum strength or 5052 for superior corrosion resistance and forming.
Can aluminum parts be anodized?
Yes. We offer clear and color Type II anodizing and hard Type III anodizing for wear resistance, in colors including black, red, blue, and gold.
What tolerances can you hold on aluminum?
Standard ISO 2768-m (±0.1 mm), with critical features down to ±0.01 mm using precision machining.
Is aluminum cheaper to machine than steel?
Usually yes — aluminum cuts 3–4× faster and tools last longer, lowering machine time and cost.
What is the difference between 6061 and 7075?
6061 is versatile, weldable, and corrosion-resistant; 7075 is much stronger (aircraft grade) but less corrosion-resistant and pricier.
Is aluminum suitable for both prototypes and production?
Yes — aluminum is ideal for rapid prototypes and scales well to low-volume production.
Related services
Explore the services that use this material:
- CNC machining services
- CNC aluminum machining
- Precision machining
- Surface finishing
- All CNC machining materials
Get your parts machined
Upload your CAD file on our Request a Quote page for a free DFM review and price — from a single prototype to low-volume production, with global shipping.