How do I know if my aluminum coil is new or old?

To determine if an aluminum coil is new or old, you can look for several signs: 1. Surface appearance: New coils typically have a clean, smooth surface without scratches or discoloration. 2. Packaging: New coils are usually well-packaged and protected. 3. Manufacturing date: Check for any labels or markings that indicate the manufacturing date. 4. Quality of the material: New coils should have consistent thickness and no signs of corrosion or wear. 5. Performance: New coils should perform as expected without any issues. If you're still unsure, consider consulting with a professional or the supplier for more information.