## Common ground
All options refer to reusable, rigid containers used for storing or transporting liquids, gases, or solids.
## Options at a glance
**7310.2X – Made of iron or steel**
- **Defining trait:** Constructed primarily from iron or steel, offering high durability and resistance to impact and pressure.
- **Typical examples:** Steel drums for chemicals, oil barrels, industrial storage tanks.
- **Best fit when:** The container must withstand heavy use, high pressure, or harsh environments.
**7612.90 – Made of aluminium**
- **Defining trait:** Constructed from aluminium, providing lightweight strength and excellent corrosion resistance.
- **Typical examples:** Aluminium cans for beverages, portable fuel drums, food-grade storage containers.
- **Best fit when:** Weight reduction and resistance to rust are critical, especially in transport or outdoor use.
## Key differences
| Feature | 7310.2X (Iron/Steel) | 7612.90 (Aluminium) |
|---------------------|------------------------|-----------------------|
| Material density | High | Low |
| Corrosion resistance| Moderate (requires coating) | High |
| Durability | Very high | High |
| Typical use | Industrial, heavy-duty | Transport, food/beverage |
## How to choose
- Is the container primarily used for heavy industrial or hazardous materials? → 7310.2X
- Does weight or corrosion resistance matter most (e.g., in transport or outdoor use)? → 7612.90
## Overlaps & pitfalls
A container may be made of aluminium but reinforced with steel parts, or a steel drum may have an aluminium lining—these could blur classification. If unsure, prioritize the **main structural material**. The defining trait is not just the material used, but which one dominates the container’s construction and function