## Common ground
All options are screw bushings made from different metallic materials.
## Options at a glance
**7318.1X – Iron or steel**
- **Defining trait:** Highest strength and wear resistance; commonly used in heavy-duty applications.
- **Typical examples:** Industrial machinery, automotive components, high-load joints.
- **Best fit when:** Durability and load-bearing capacity are critical.
**7415.33 – Copper**
- **Defining trait:** Excellent thermal and electrical conductivity; resists galling.
- **Typical examples:** Electrical connectors, heat exchangers, precision instruments.
- **Best fit when:** Conductivity or low friction in dynamic joints is needed.
**7508.90 – Nickel**
- **Defining trait:** High corrosion and heat resistance; maintains strength at elevated temperatures.
- **Typical examples:** Aerospace parts, chemical processing equipment.
- **Best fit when:** Exposure to harsh environments or high heat.
**7616.10 – Aluminium**
- **Defining trait:** Lightweight with good machinability; moderate strength.
- **Typical examples:** Consumer electronics, lightweight machinery, aerospace (non-load-bearing).
- **Best fit when:** Weight reduction is a priority.
**7907.00 – Zinc**
- **Defining trait:** Low melting point; often used for plating or sacrificial protection.
- **Typical examples:** Galvanized fasteners, low-stress bushings in non-critical applications.
- **Best fit when:** Cost-effective, low-load use with corrosion resistance via coating.
**8101.99 – Tungsten**
- **Defining trait:** Extreme hardness and high melting point; very dense.
- **Typical examples:** High-wear tooling, radiation shielding components.
- **Best fit when:** Maximum wear resistance or extreme temperature use.
**8102.99 – Molybdenum**
- **Defining trait:** High thermal stability and strength at high temperatures.
- **Typical examples:** Vacuum furnace parts, high-temp bearings.
- **Best fit when:** Operation under extreme heat without deformation.
**8104.90 – Magnesium**
- **Defining trait:** Lightest metal; low density but lower strength and flammable.
- **Typical examples:** Aerospace components (non-critical), portable devices.
- **Best fit when:** Weight savings outweigh strength needs.
**8108.90 – Titanium**
- **Defining trait:** High strength-to-weight ratio and excellent corrosion resistance.
- **Typical examples:** Medical implants, aerospace, marine applications.
- **Best fit when:** Need for lightweight, durable, and corrosion-resistant performance.
## Key differences
| Material | Strength | Weight | Corrosion Resistance | Heat Resistance |
|----------------|----------|--------|------------------------|------------------|
| Iron/Steel | Very High | High | Moderate | Moderate |
| Copper | Low | Medium | Good | Low |
| Nickel | High | Medium | Very High | Very High |
| Aluminium | Medium | Low | Moderate | Low |
| Zinc | Low | Medium | Good (via coating) | Low |
| Tungsten | Extreme | Very High | Low | Extremely High |
| Molybdenum | High | Medium | Good | Extremely High |
| Magnesium | Low | Very Low | Poor | Low |
| Titanium | High | Low | Excellent | High |
## How to choose
- Is high strength and wear resistance required? → 7318.1X
- Is electrical or thermal conductivity important? → 7415.33
- Is the environment corrosive or hot? → 7508.90 or 8102.99
- Is weight a major concern? → 7616.10 or 8108.90
- Is cost and low-load use key? → 7907.00
## Overlaps & pitfalls
A bushing may combine traits (e.g., titanium is strong, light, and corrosion-resistant). If multiple options fit, prioritize the **main function**—e.g., use 8108.90 for aerospace due to strength-to-weight ratio, not just corrosion resistance. No option is vague; all are clearly material-based