## Common ground
All options are wood screws classified by their material composition.
## Options at a glance
**7318.1X – Iron or steel**
- **Defining trait:** Most common material for general-purpose wood screws; offers high strength and affordability.
- **Typical examples:** Standard construction screws, drywall screws (steel).
- **Best fit when:** Used in typical woodworking, framing, or indoor applications requiring durability.
**7415.33 – Copper**
- **Defining trait:** Corrosion-resistant and electrically conductive; used where aesthetics or environmental resistance matter.
- **Typical examples:** Outdoor furniture, marine fixtures, decorative hardware.
- **Best fit when:** Environment is humid or corrosive, or visual appeal is key.
**7508.90 – Nickel**
- **Defining trait:** High corrosion and wear resistance; often used for durability in harsh conditions.
- **Typical examples:** Industrial equipment, high-end fixtures, marine hardware.
- **Best fit when:** Long-term exposure to moisture or chemicals is expected.
**7616.10 – Aluminium**
- **Defining trait:** Lightweight and corrosion-resistant; not as strong as steel but ideal for weight-sensitive uses.
- **Typical examples:** Aircraft parts, lightweight furniture, outdoor signage.
- **Best fit when:** Weight reduction is critical and high strength isn’t required.
**7907.00 – Zinc**
- **Defining trait:** Often used as a coating (galvanization), not typically for solid screws; may refer to zinc-plated steel.
- **Typical examples:** Galvanized nails or screws (coated, not pure zinc).
- **Best fit when:** The screw is coated for rust protection, but not made entirely of zinc.
**8101.99 – Tungsten**
- **Defining trait:** Extremely hard and dense; rarely used in standard wood screws due to cost and brittleness.
- **Typical examples:** Specialized tools or high-wear applications (not typical for wood).
- **Best fit when:** Unusual, high-abrasion environments (e.g., industrial machinery).
**8102.99 – Molybdenum**
- **Defining trait:** High melting point and strength; used in extreme conditions, not standard wood screws.
- **Typical examples:** Aerospace or high-temp components.
- **Best fit when:** Extreme heat or stress resistance is needed (rare for wood).
**8104.90 – Magnesium**
- **Defining trait:** Very lightweight; prone to corrosion and low strength; not common in structural applications.
- **Typical examples:** Aerospace components, temporary fasteners.
- **Best fit when:** Weight is critical and load is minimal.
**8108.90 – Titanium**
- **Defining trait:** Excellent strength-to-weight ratio and corrosion resistance; expensive but durable.
- **Typical examples:** High-end outdoor gear, medical implants, marine hardware.
- **Best fit when:** Longevity, light weight, and resistance to rust are essential.
## Key differences
| Material | Strength | Weight | Corrosion Resistance | Common Use Case |
|----------------|----------|----------|------------------------|----------------------------|
| Iron/Steel | High | Medium | Low (unless coated) | General construction |
| Copper | Medium | High | Very high | Decorative, marine |
| Nickel | High | Medium | Very high | Industrial, harsh env. |
| Aluminium | Low | Low | High | Lightweight structures |
| Zinc | Low | Medium | Moderate (coated) | Coated fasteners |
| Tungsten | Very high| High | High | Extreme wear (not wood) |
| Molybdenum | Very high| Medium | High | High-temp applications |
| Magnesium | Very low | Very low | Low | Temporary or aerospace |
| Titanium | High | Low | Very high | Premium, long-life uses |
## How to choose
- Is the screw used in a humid or outdoor environment? → 7415.33, 7508.90, 7616.10, 8108.90
- Does weight matter more than strength? → 7616.10, 8104.90
- Is it for general indoor use? → 7318.1X
- Is it coated (e.g., galvanized)? → 7907.00 (likely a coating)
- Is it high-end or used in extreme conditions? → 8108.90, 8102.99
## Overlaps & pitfalls
- Zinc (7907.00) is often a coating, not solid; may overlap with steel (7318.1X).
- Titanium and nickel are both corrosion-resistant but differ in strength and cost.
- Tungsten, molybdenum, and magnesium are rarely used for wood screws—may indicate non-standard or specialized use.
- **No clear priority**: Choose based on the product’s MAIN function (e.g., strength vs. weight vs. environment)