## Common ground
All options are screw hooks and screw rings classified by their base metal material.
## Options at a glance
**7318.13 – Iron or steel**
- **Defining trait:** Made from iron or steel, offering high strength and durability.
- **Typical examples:** Heavy-duty lifting hooks, industrial rigging rings.
- **Best fit when:** High load capacity and cost-effectiveness are priorities.
**7415.39 – Copper**
- **Defining trait:** Made from copper, known for corrosion resistance and electrical conductivity.
- **Typical examples:** Marine fittings, electrical grounding hardware.
- **Best fit when:** Use in corrosive environments or where electrical properties matter.
**7508.90 – Nickel**
- **Defining trait:** Made from nickel, offering excellent corrosion and heat resistance.
- **Typical examples:** Aerospace components, chemical processing equipment.
- **Best fit when:** High-temperature or highly corrosive conditions.
**7616.10 – Aluminium**
- **Defining trait:** Made from aluminium, lightweight with good corrosion resistance.
- **Typical examples:** Outdoor signage hooks, temporary rigging.
- **Best fit when:** Weight reduction is critical and loads are moderate.
**7907.00 – Zinc**
- **Defining trait:** Made from zinc, often used for galvanizing or low-cost applications.
- **Typical examples:** Coated fasteners, decorative hardware.
- **Best fit when:** Low cost and basic protection needed; not for high stress.
**8101.99 – Tungsten**
- **Defining trait:** Made from tungsten, extremely dense and strong but brittle.
- **Typical examples:** Specialized industrial tools, radiation shielding.
- **Best fit when:** Extreme hardness or density required (rare use for hooks/rings).
**8102.99 – Molybdenum**
- **Defining trait:** Made from molybdenum, high melting point and heat resistance.
- **Typical examples:** High-temp furnace components, aerospace parts.
- **Best fit when:** Extreme temperature environments.
**8104.90 – Magnesium**
- **Defining trait:** Made from magnesium, very light but flammable in powder form.
- **Typical examples:** Aerospace lightweight fittings (rare).
- **Best fit when:** Ultra-lightweight needs and non-flammable conditions.
**8108.90 – Titanium**
- **Defining trait:** Made from titanium, strong, lightweight, and highly corrosion-resistant.
- **Typical examples:** Marine hardware, medical implants, high-performance gear.
- **Best fit when:** High strength-to-weight ratio and long-term durability needed.
## Key differences
| Material | Strength | Weight | Corrosion Resistance | Cost |
|--------------|----------|---------|------------------------|------------|
| Iron/Steel | Very High| Medium | Low (unless coated) | Low |
| Copper | Medium | Medium | High | Medium |
| Nickel | High | Medium | Very High | High |
| Aluminium | Medium | Low | High | Medium |
| Zinc | Low | Medium | Medium (coated) | Low |
| Tungsten | Very High| High | High | Very High |
| Molybdenum | High | Medium | High | Very High |
| Magnesium | Low | Very Low| Medium | Medium |
| Titanium | High | Low | Very High | Very High |
## How to choose
- Is the application in a corrosive environment (e.g., marine, chemical)? → 7415.39, 7508.90, 7616.10, 8108.90
- Do you need maximum strength and durability? → 7318.13, 8101.99, 8102.99
- Is weight a critical factor? → 7616.10, 8104.90, 8108.90
- Is cost the main concern? → 7318.13, 7907.00
## Overlaps & pitfalls
Some materials (e.g., aluminium, titanium) may be used in similar applications (lightweight, corrosion-resistant), but differ in strength and cost. Tungsten and molybdenum are rarely used for standard hooks/rings due to brittleness and cost. If unsure, prioritize the material’s **main functional advantage**—e.g., strength, weight, or corrosion resistance—over price or availability