## Common ground
All options are raw metal materials used to manufacture bolts and nuts, differing only in the base metal.
## Options at a glance
**7318.1X – Iron or steel**
- **Defining trait:** Most common material due to high strength and low cost.
- **Typical examples:** Standard hex bolts, machine screws, structural fasteners.
- **Best fit when:** General-purpose use, high load-bearing needs, or cost efficiency is key.
**7415.33 – Copper**
- **Defining trait:** Excellent electrical conductivity and corrosion resistance.
- **Typical examples:** Electrical connectors, marine hardware, decorative fasteners.
- **Best fit when:** Conductivity or resistance to saltwater corrosion is required.
**7508.90 – Nickel**
- **Defining trait:** High heat and corrosion resistance; often used in alloys.
- **Typical examples:** Aerospace components, high-temperature environments.
- **Best fit when:** Extreme durability or resistance to oxidation under stress.
**7616.10 – Aluminium**
- **Defining trait:** Lightweight with moderate strength; resists corrosion.
- **Typical examples:** Aircraft parts, automotive fittings, outdoor fixtures.
- **Best fit when:** Weight reduction is critical and loads are moderate.
**7907.00 – Zinc**
- **Defining trait:** Often used as a coating (e.g., galvanizing), not typically for structural blanks.
- **Typical examples:** Galvanized bolts, sacrificial coatings.
- **Best fit when:** Corrosion protection via plating is the main purpose.
**8101.99 – Tungsten**
- **Defining trait:** Extremely high density and melting point; rare in fasteners.
- **Typical examples:** Specialized industrial tools, radiation shielding.
- **Best fit when:** Unusual applications requiring extreme hardness or density.
**8102.99 – Molybdenum**
- **Defining trait:** High-temperature strength and resistance to creep.
- **Typical examples:** Aerospace or nuclear components.
- **Best fit when:** Operating in very high-temperature environments.
**8104.90 – Magnesium**
- **Defining trait:** Lightest structural metal; prone to corrosion.
- **Typical examples:** High-performance racing parts, aerospace.
- **Best fit when:** Weight savings outweigh durability concerns.
**8108.90 – Titanium**
- **Defining trait:** Excellent strength-to-weight ratio and corrosion resistance.
- **Typical examples:** Jet engines, medical implants, high-end sports equipment.
- **Best fit when:** Performance and longevity in harsh environments are essential.
## Key differences
| Material | Strength | Weight | Corrosion Resistance | Cost |
|----------------|----------|---------|------------------------|----------|
| Iron/Steel | High | Medium | Low (unless coated) | Low |
| Copper | Medium | Medium | Very High | Medium |
| Nickel | High | Medium | Very High | High |
| Aluminium | Medium | Low | High | Medium |
| Zinc | Low | Medium | High (as coating) | Low |
| Tungsten | Very High| Very High| High | Very High|
| Molybdenum | High | Medium | High | Very High|
| Magnesium | Low | Very Low| Low | Medium |
| Titanium | High | Low | Very High | Very High|
## How to choose
- Is the primary need high strength and low cost? → 7318.1X
- Does the application require electrical conductivity or marine use? → 7415.33
- Is corrosion resistance in extreme conditions critical? → 7508.90 or 8108.90
- Is weight reduction essential? → 7616.10 or 8104.90
- Is the product for specialized high-temp or high-density use? → 8101.99 or 8102.99
## Overlaps & pitfalls
- Zinc (7907.00) is rarely used as a structural blank; it's typically a coating. Confusion may arise if the product is galvanized but not pure zinc.
- Titanium and nickel both offer high corrosion resistance, but titanium has better strength-to-weight ratio.
- No option clearly prioritizes alloy vs. pure metal—user must decide based on material specification.
- If unsure, **7318.1X (iron/steel)** is the default for most standard fasteners