Aluminum at a Glance
Aluminum is one of the most commonly specified metals for CNC machined parts, combining low weight, useful strength, and excellent machinability. This page is designed for engineers and buyers who are shortlisting materials and need reliable reference data on aluminum grades, design behavior, and finish compatibility before requesting CNC machining.
Why Use Aluminum for CNC Machining
Aluminum sits in a useful middle ground between plastics and steels in terms of strength, stiffness, and cost. It allows engineers to reduce part weight without moving to more expensive materials and can generally be machined faster than most steels, which helps keep lead times and per‑part cost under control. Because of this balance, aluminum is widely used for:
- Mechanical housings and enclosures
- Structural brackets, frames, and mounts
- Fixtures, tooling plates, and jigs
- Thermal components such as heatsinks and heat‑spreading plates
- Lightweight components in automotive, machinery, and aerospace applications
This page focuses on aluminum as a material choice for CNC machining and how to use it effectively in your designs.
Design Considerations for Aluminum Parts
Use the following values as general design guidelines for CNC‑machined aluminum parts. Actual limits depend on alloy, part size, fixturing, and tooling. For designs that need to push beyond these ranges, Clarwe can review your CAD data and advise on achievable tolerances and potential design adjustments.
| Design aspect | Recommended guideline for aluminum CNC parts |
|---|---|
| Minimum wall thickness (standard) | ≈ 0.8 – 1.0 mm for most walls |
| Minimum wall thickness (feasible) | Down to ≈ 0.5 mm in localized areas |
| Maximum wall height‑to‑thickness ratio | Aim for ≤ 8:1 where possible |
| Minimum internal corner fillet radius | ≥ 0.5 – 1.0 mm in shallow pockets |
| Deep pocket fillet radius | At least 1/3 of pocket depth as a starting point |
| Practical minimum hole diameter (standard) | ≈ 2.5 mm |
| Practical minimum hole diameter (feasible) | Down to ≈ 1.0 mm with appropriate tooling |
| Threaded hole size | Prefer M3 and larger for most designs |
| Distribution of tight tolerances | Apply tight tolerances only to critical features |
Surface Finish Compatibility
Aluminum is highly compatible with a wide range of surface treatments, which is one of the reasons it is so popular as a CNC material. Common finish directions include:
- As‑machined surfaces, suitable for internal or non‑cosmetic parts
- Bead‑blasted matte surfaces for a more uniform appearance
- Clear or color anodizing to combine corrosion resistance with a controlled aesthetic
- Hard anodizing where additional wear resistance is required
- Painting or powder coating for color‑critical or branding‑driven applications
When planning finishes, it is important to keep in mind that some treatments add measurable thickness to the surface. For example, anodizing and powder coating can affect tight fits, small clearances, and threaded regions. Critical dimensions should be defined with the finishing sequence in mind.
How to Use the Alloy Tables on This Page
The aluminum alloy tables on this page list the specific grades available at Clarwe together with key mechanical and physical properties. Rather than choosing an alloy by name alone, it is best to start from the requirements of your application and match them to the values and notes in these tables. As a starting point, many designs consider:
- A general‑purpose structural alloy such as 6061 or 6082 for balanced strength and machinability
- A higher‑strength alloy such as 7075 for weight‑sensitive parts under higher loads
- A corrosion‑resistant alloy such as 5052 or 5083 for marine or demanding outdoor environments
For example, you can:
- Look for higher strength grades where structural loading and weight reduction are priorities
- Favor more corrosion‑resistant grades where parts will be exposed to humidity, chemicals, or marine environments
- Choose alloys with good formability if subsequent bending or forming operations are planned
- Consider machinability and typical applications notes where cycle time and surface quality are especially important
If multiple alloys appear to fit, you can shortlist a few and evaluate them against cost, availability, and any secondary processes required.
| Material | Density (g/cm³) | Yield Strength (MPa) | Tensile Strength (MPa) | Elongation at Break (%) | Hardness (Brinell) (HBW) | Fatigue Strength (MPa) |
|---|---|---|---|---|---|---|
| Aluminum 2014 | 2.78 - 2.82 | 100 - 430 | 190 - 490 | 6 - 18 | 45 - 140 | 90 - 140 |
| Aluminum 2014-T6 | 2.8 - 3 | 400 - 430 | 460 - 500 | 7 - 13 | 130 - 150 | 120 - 140 |
| Aluminum 2017A | 2.75 - 2.80 | 110 - 280 | 200 - 420 | 6 - 18 | 55 - 120 | 90 - 130 |
| Aluminum 2024-T351 | 2.72 - 2.80 | 320 - 340 | 450 - 480 | 10 - 19 | 120 - 145 | 100 - 140 |
| Aluminum 5052 | 2.66 - 2.70 | 90 - 220 | 190 - 280 | 10 - 22 | 46 - 70 | 100 - 130 |
| Aluminum 5052-H32 | 2.65 - 2.7 | 170 - 200 | 210 - 260 | 10 - 20 | 55 - 65 | 110 - 125 |
| Aluminum 5083-H111 | 2.66 - 2.78 | 125 - 165 | 210 - 300 | 10 - 15 | 60 - 80 | 120 - 150 |
| Aluminum 5083-H32 | 2.65 - 2.7 | 230 - 260 | 310 - 340 | 9 - 15 | 80 - 95 | 110 - 170 |
| Aluminum 6061 | ∼ 2.70 | 240 - 280 | 290 - 320 | 10 - 15 | 90 - 100 | 90 - 120 |
| Aluminum 6061-T6 | ∼ 2.70 | 240 - 280 | 290 - 320 | 8 - 14 | 90 - 100 | 90 - 110 |
| Aluminum 6061-T651 | 2.7 - 2.71 | 240 - 280 | 270 - 320 | 10 - 17 | 90 - 100 | 95 - 110 |
| Aluminum 6063 | ∼ 2.70 | 90 - 130 | 130 - 180 | 8 - 18 | 40 - 60 | 55 - 80 |
| Aluminum 6063 -T5 | ∼ 2.70 | 140 - 150 | 180 - 190 | 10 - 15 | 55 - 70 | 65 - 75 |
| Aluminum 6063 -T6 | ∼ 2.70 | 160 - 215 | 190 - 245 | 8 - 12 | 70 - 80 | 65 - 75 |
| Aluminum 6082 | 2.70 - 2.71 | 240 - 280 | 290 - 340 | 8 - 15 | 90 - 100 | 80 - 120 |
| Aluminum 6082-T6 | ∼ 2.70 | 250 - 280 | 295 - 340 | 8 - 12 | 90 - 105 | 90 - 130 |
| Aluminum 6082-T651 | 2.70 - 2.71 | 260 - 310 | 300 - 340 | 8 - 12 | 89 - 95 | 90 - 120 |
| Aluminum 7050 | 2.7 - 2.8 | 390 - 500 | 490 - 570 | 8 - 12 | 130 - 150 | 150 - 230 |
| Aluminum 7075-T651 | 2.7 - 2.85 | 480 - 505 | 540 - 570 | 8 - 12 | 140 - 160 | 150 - 170 |
| Aluminum 7075-T7351 | 2.8 - 2.82 | 410 - 440 | 500 - 530 | 7 - 12 | 130 - 150 | 150 - 170 |
| Aluminum 7075-T6 | 2.80 - 2.82 | 480 - 505 | 540 - 575 | 7 - 11 | 140 - 160 | 150 - 170 |
| Aluminum MIC6 | ∼2.7 | 100 - 110 | 160 - 170 | ∼3 | 65 | 50 - 60 |
When Aluminum Is a Good Fit (and When It Isn’t)
- Part weight needs to be reduced without moving to very exotic materials
- You need metal parts with good machinability and reasonably short lead times
- Corrosion resistance and finish options are important design factors
Other materials may be more suitable when:
- Very high surface hardness or abrasion resistance is required without coatings (often better served by tool steels or hardened stainless steels)
- Parts must operate at sustained high temperatures where aluminum’s strength drops and high‑temperature alloys or steels perform better
In borderline cases, it is often useful to compare a candidate aluminum alloy against a steel, stainless steel, or engineering plastic option and evaluate trade‑offs in strength, weight, environment, and cost.
After selecting a suitable aluminum grade from the table, you can upload your 3D model and drawings, specify the alloy and any finishes, and request CNC machining directly from Clarwe.