5000 series aluminium alloy vs 6000 series aluminium alloy
5000 series aluminium alloy and 6000 series aluminium alloy are genuine alternatives to one another — a choice somebody actually makes — and differ on 3 measured properties, density most clearly.
5000 series aluminium alloy vs 6000 series aluminium alloy
5000 series aluminium alloy
Aluminium with magnesium in it — the marine alloy, and the one that welds properly.
6000 series aluminium alloy
The aluminium everything is extruded from — window frames, bike frames, heat sinks and structural profile.
| Property | 5000 series aluminium alloy | 6000 series aluminium alloy |
|---|---|---|
| Density | 2.64–2.69 g/cm³ | 2.68–2.72 g/cm³ higher |
| Melting point | 570–640 °C | 580–650 °C higher |
| Tensile strength These are values for different forms — annealed to strain-hardened (O to H38 tempers) and annealed (O) to peak-aged (T6) — so the numbers describe different substances rather than a difference between them. | 180–380 MPa | 125–340 MPa |
| Young's modulus Only one of the two has a figure we can stand behind, so there is nothing to compare. | Not known | 69 GPa |
Choosing between them
5000 series aluminium alloy is recorded as a substitute for 6000 series aluminium alloy — more corrosion-resistant, easier to work.
What it gives up: Not heat-treatable, so it cannot be aged to strength, and it extrudes poorly — profile is the 6000 series' whole reason for existing.
In this application, on the evidence cited above.