## Common ground
All options are screws made from different metallic materials.
## Options at a glance
**7318.1X – Iron or steel**
- **Defining trait:** Most common and cost-effective base material; offers high strength and durability.
- **Typical examples:** Machine screws, lag bolts, hex head screws.
- **Best fit when:** General-purpose use, structural applications, or where strength is key.
**7415.33 – Copper**
- **Defining trait:** Naturally corrosion-resistant and electrically conductive.
- **Typical examples:** Electrical connectors, marine hardware, decorative fasteners.
- **Best fit when:** Applications requiring conductivity or resistance to moisture/corrosion.
**7508.90 – Nickel**
- **Defining trait:** High corrosion and heat resistance; often used in coatings or alloys.
- **Typical examples:** Aerospace components, high-temperature environments.
- **Best fit when:** Harsh environments or where surface durability is critical.
**7616.10 – Aluminium**
- **Defining trait:** Lightweight with good corrosion resistance; non-magnetic.
- **Typical examples:** Aircraft parts, electronics, outdoor fixtures.
- **Best fit when:** Weight reduction needed or in non-ferrous applications.
**7907.00 – Zinc**
- **Defining trait:** Often used as a coating (e.g., galvanized) rather than pure material; provides sacrificial protection.
- **Typical examples:** Galvanized screws, outdoor fasteners.
- **Best fit when:** Corrosion protection is primary, especially in exposed environments.
**8101.99 – Tungsten**
- **Defining trait:** Extremely hard and dense; used in specialized high-wear applications.
- **Typical examples:** Cutting tools, wear-resistant fasteners (rare for screws).
- **Best fit when:** Extreme hardness or wear resistance is required.
**8102.99 – Molybdenum**
- **Defining trait:** High melting point and strength at elevated temperatures.
- **Typical examples:** High-temp industrial equipment, aerospace.
- **Best fit when:** Operating in high-temperature environments.
**8104.90 – Magnesium**
- **Defining trait:** Very lightweight; prone to corrosion and flammability.
- **Typical examples:** Aerospace or automotive components (rare for screws).
- **Best fit when:** Weight-critical applications with controlled environment.
**8108.90 – Titanium**
- **Defining trait:** Excellent strength-to-weight ratio and corrosion resistance.
- **Typical examples:** Medical implants, aerospace, marine hardware.
- **Best fit when:** High performance, lightweight, and long-term durability needed.
## Key differences
| Option | Material | Weight | Corrosion Resistance | Common Use Case |
|-------|----------|--------|------------------------|------------------|
| 7318.1X | Iron/Steel | Medium | Low (unless coated) | General use |
| 7415.33 | Copper | Medium | High | Electrical, marine |
| 7508.90 | Nickel | Medium | Very high | Harsh environments |
| 7616.10 | Aluminium | Light | High | Lightweight applications |
| 7907.00 | Zinc | Medium | High (as coating) | Corrosion protection |
| 8101.99 | Tungsten | Heavy | High | Wear resistance |
| 8102.99 | Molybdenum | Medium | High | High temp |
| 8104.90 | Magnesium | Very light | Low | Specialized, controlled use |
| 8108.90 | Titanium | Light | Very high | High-performance |
## How to choose
- Is the screw used in a corrosive or outdoor environment? → 7415.33, 7616.10, 7907.00, 8108.90
- Does weight matter most? → 7616.10, 8104.90, 8108.90
- Is high strength or hardness required? → 7318.1X, 8101.99
- Is it for electrical conductivity? → 7415.33
- Is it in aerospace, medical, or marine use? → 7616.10, 8108.90
## Overlaps & pitfalls
- Zinc (7907.00) is often a coating; pure zinc screws are rare—check if the screw is galvanized.
- Titanium and aluminium may be mistaken for each other due to light weight; use material specs.
- No option clearly prioritizes cost, so choose based on **main function**: strength (steel), corrosion resistance (copper/titanium), or lightness (aluminium/titanium)