## Common ground
All options refer to metallic nuts used in mechanical fastening, differing only by material.
## Options at a glance
**7318.16 – Iron/steel**
- **Defining trait:** Most common and cost-effective; offers high strength and durability.
- **Typical examples:** Standard hex nuts for machinery, automotive assemblies.
- **Best fit when:** High load-bearing needs, general industrial use, budget-conscious applications.
**7415.33 – Copper**
- **Defining trait:** Excellent electrical conductivity and corrosion resistance.
- **Typical examples:** Electrical connectors, marine hardware, high-purity environments.
- **Best fit when:** Electrical grounding or environments where oxidation must be avoided.
**7508.90 – Nickel**
- **Defining trait:** High corrosion and heat resistance; used in extreme conditions.
- **Typical examples:** Aerospace components, chemical processing equipment.
- **Best fit when:** Exposure to harsh chemicals, high temperatures, or saltwater.
**7616.10 – Aluminium**
- **Defining trait:** Lightweight with good corrosion resistance; non-magnetic.
- **Typical examples:** Aircraft parts, electronic enclosures, outdoor fixtures.
- **Best fit when:** Weight reduction is critical or magnetic interference must be avoided.
**7907.00 – Zinc**
- **Defining trait:** Often used as a coating (galvanized), but solid zinc nuts are rare and brittle.
- **Typical examples:** Decorative or low-stress applications; not common in structural use.
- **Best fit when:** Non-load-bearing, aesthetic, or temporary fastening.
**8101.99 – Tungsten**
- **Defining trait:** Extremely high density and strength; very hard but brittle.
- **Typical examples:** Specialized high-stress tools, aerospace (rare).
- **Best fit when:** Unusual need for extreme hardness or density in niche applications.
**8102.99 – Molybdenum**
- **Defining trait:** High melting point and strength at elevated temperatures.
- **Typical examples:** High-temperature furnace components, aerospace.
- **Best fit when:** Operating in high-heat environments (e.g., engines, reactors).
**8104.90 – Magnesium**
- **Defining trait:** Lightest metal; prone to corrosion and flammability.
- **Typical examples:** Aerospace or racing vehicle parts (rare).
- **Best fit when:** Maximum weight savings in non-corrosive, controlled environments.
**8108.90 – Titanium**
- **Defining trait:** Excellent strength-to-weight ratio and corrosion resistance.
- **Typical examples:** Aircraft, medical implants, high-performance sports equipment.
- **Best fit when:** Critical performance with weight and durability balance.
## Key differences
| Material | Strength | Weight | Corrosion Resistance | Heat Resistance | Common Use Case |
|----------------|----------|--------|------------------------|------------------|----------------------------|
| Iron/Steel | High | Medium | Moderate | Low | General industrial |
| Copper | Medium | Medium | Very High | Low | Electrical, marine |
| Nickel | High | Medium | Very High | High | Harsh environments |
| Aluminium | Medium | Low | High | Medium | Lightweight applications |
| Zinc | Low | Medium | Moderate | Low | Decorative, temporary |
| Tungsten | Very High| High | High | Very High | Extreme stress |
| Molybdenum | High | Medium | High | Very High | High-temperature use |
| Magnesium | Low | Very Low | Low | Low | Specialized lightweight |
| Titanium | High | Low | Very High | High | Aerospace, medical |
## How to choose
- Is the application in a corrosive or high-heat environment? → 7508.90, 8102.99, 8108.90
- Does weight matter most? → 7616.10, 8104.90
- Is electrical conductivity required? → 7415.33
- Is strength and durability the top priority? → 7318.16, 8101.99
- Is it for aerospace or medical use? → 8108.90
## Overlaps & pitfalls
- Some materials (e.g., titanium, nickel) can serve multiple high-performance roles.
- Zinc and magnesium nuts are rare; their use may indicate a special requirement.
- No clear priority: choose based on the **main function**—e.g., weight vs. strength vs. environment