## Common ground
All options are drive screws classified by their primary material.
## Options at a glance
**7318.1X – Iron or steel**
- **Defining trait:** Most common base material, offering high strength and affordability.
- **Typical examples:** Standard machine screws, lag screws, hex bolts.
- **Best fit when:** General-purpose use where cost and durability are key.
**7415.33 – Copper**
- **Defining trait:** Excellent electrical conductivity and corrosion resistance.
- **Typical examples:** Electrical grounding screws, specialized connectors.
- **Best fit when:** Applications requiring electrical conduction or resistance to corrosion in harsh environments.
**7508.90 – Nickel**
- **Defining trait:** High corrosion and heat resistance; often used for plating.
- **Typical examples:** Aerospace fasteners, high-temperature applications.
- **Best fit when:** Need for durability in extreme conditions or decorative finish.
**7616.10 – Aluminium**
- **Defining trait:** Lightweight with good corrosion resistance.
- **Typical examples:** Aircraft components, consumer electronics.
- **Best fit when:** Weight reduction is critical and strength demands are moderate.
**7907.00 – Zinc**
- **Defining trait:** Often used as a coating (galvanization), not typically for structural screws.
- **Typical examples:** Galvanized screws for outdoor use.
- **Best fit when:** Corrosion protection via plating, not bulk material.
**8101.99 – Tungsten**
- **Defining trait:** Extremely high density and hardness; rare in standard fasteners.
- **Typical examples:** Specialized industrial or military applications.
- **Best fit when:** Unusual need for extreme hardness or weight (e.g., vibration damping).
**8102.99 – Molybdenum**
- **Defining trait:** High melting point and strength at elevated temperatures.
- **Typical examples:** High-temperature furnace components.
- **Best fit when:** Extreme heat resistance required (rare in standard screws).
**8104.90 – Magnesium**
- **Defining trait:** Very light, but prone to corrosion and flammability.
- **Typical examples:** Aerospace or racing parts where weight is critical.
- **Best fit when:** Ultra-lightweight design with low load requirements.
**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 in corrosive or weight-sensitive environments.
## Key differences
| Material | Strength | Weight | Corrosion Resistance | Common Use Case |
|----------------|----------|--------|------------------------|----------------------------|
| Iron/Steel | High | Medium | Low (unless coated) | General fastening |
| Copper | Medium | Medium | High | Electrical connections |
| Nickel | High | Medium | Very high | Harsh environments |
| Aluminium | Medium | Low | High | Lightweight applications |
| Zinc | Low | Medium | High (as coating) | Corrosion protection |
| Tungsten | Very high| Very high | Medium | Extreme hardness/weight |
| Molybdenum | High | Medium | Medium | High-temperature use |
| Magnesium | Low | Very low | Low (reactive) | Ultra-lightweight parts |
| Titanium | High | Low | Very high | Medical, aerospace |
## How to choose
1. Is the screw used in electrical applications? → 7415.33
2. Does it need to resist corrosion in harsh environments? → 7508.90 or 7616.10 or 8108.90
3. Is weight a critical factor? → 7616.10 or 8104.90 or 8108.90
4. Is extreme strength or heat resistance required? → 8101.99 or 8102.99
## Overlaps & pitfalls
- Zinc (7907.00) is often a coating, not bulk material—confusion with galvanized steel screws.
- Titanium and nickel both offer high corrosion resistance but differ in weight and cost.
- No single priority rule: choose based on the **main function** (e.g., electrical vs. structural vs. lightweight)