## Common ground
All options refer to galle chains (a type of flexible, interlocking chain used in marine or industrial settings), differing only in material composition.
## Options at a glance
**7315.1X – Made of iron or steel**
- **Defining trait:** Highest strength and durability; resistant to wear and heavy loads.
- **Typical examples:** Ship mooring chains, crane lifting chains.
- **Best fit when:** Need for high tensile strength and resistance to corrosion (e.g., marine use with protective coating).
**7419 – Made of copper**
- **Defining trait:** Non-magnetic and corrosion-resistant; used where electrical or magnetic interference must be avoided.
- **Typical examples:** Marine fittings in sensitive equipment, decorative chains in saltwater environments.
- **Best fit when:** Applications requiring non-magnetic properties or resistance to seawater corrosion without coating.
**7616.9X – Made of aluminium**
- **Defining trait:** Lightweight and corrosion-resistant; lower strength than steel or copper.
- **Typical examples:** Temporary rigging, lightweight lifting systems, decorative marine use.
- **Best fit when:** Weight is a critical factor and load capacity is moderate.
## Key differences
| Feature | Iron/Steel (7315.1X) | Copper (7419) | Aluminium (7616.9X) |
|------------------|------------------------|--------------------|-----------------------|
| Strength | Very high | Medium | Low |
| Weight | Heavy | Medium | Light |
| Corrosion resistance | Moderate (needs coating) | High | High |
| Magnetic? | Yes | No | No |
## How to choose
- Is the chain used for heavy lifting or mooring? → 7315.1X
- Does it need to be non-magnetic or resist seawater without coating? → 7419
- Is weight a major concern and load moderate? → 7616.9X
## Overlaps & pitfalls
A chain may fit multiple categories if, for example, it’s made of copper but used in heavy-duty applications (still fits 7419). However, material is the primary classifier here. If unsure, prioritize the **main functional requirement**: strength (steel), non-magnetism (copper), or lightness (aluminium). No option is vague