1. From surface: Due to the different processing methods, the surface of 7000 series aluminum tubes is much darker than 6000 series. The surface of 7000 series appears similar to black, while the surface of 6000 series aluminum tubes is silver-white like most aluminum.
2. From sound: As the hardness of the 7000 series tubes is close to that of steel, it is much higher than that of the 6000 series aluminum tubes. Therefore, when they fall to the ground, the sound of the 7000 series tubes will be more shrill and sharp than 6000 series tubes
3. Test mechanical properties: We can have their mechanical properties tested at an experimental institution. Generally, for 7000 series tubes, the tensile strength is greater than or equal to 540, and the yield strength is greater than or equal to 485. For 6000 series tubes, the tensile strength is greater than or equal to 250, and the yield strength is greater than or equal to 240.
Mechanical Properties
| Tensile Strength( σb (MPa)) | Yield strength( σ0.2 (MPa)) | Elongation(%) | |
| 6063-T5 | ≥175 | ≥130 | ≥8 |
| 6061-T6 | ≥260 | ≥240 | ≥8 |
| 7075-T6 | ≥540 | ≥485 | ≥7 |
| 7075-O | ≤275 | ≤165 | ≥10 |
4. Chemical composition testing: Generally, the Zn content in 7000 series is 5.1 – 5.6, while that in 6061 is 0.25.
| % | Si | Fe | Cu | Mn | Mg | Cr | Zn | Ti | Other | AL |
| 6061 | 0.4-0.8 | 0.7 | 0.15-0.4 | 0.15 | 0.8-1.2 | 0.04-0.35 | 0.25 | 0.15 | / | 95.8–98.6 |
| 7075 | 0.4 | 0.5 | 1.2-2.0 | 0.3 | 2.1-2.9 | 0.18-0.28 | 5.1-5.6 | 0.2 | / | 87.1-91.4 |
