## Common ground
All options are door thresholds made from different materials, used to seal gaps under doors for insulation, safety, or accessibility.
## Options at a glance
**3925.20 – Plastic**
- **Defining trait:** Made primarily from synthetic polymers like PVC or polyethylene.
- **Typical examples:** Flexible plastic strips, low-cost residential thresholds.
- **Best fit when:** Budget-friendly, moisture-resistant, or lightweight installation is needed.
**4418.1X,4418.2X – Wood**
- **Defining trait:** Crafted from natural wood (e.g., pine, oak), often finished or treated.
- **Typical examples:** Wooden door sills in traditional homes or offices.
- **Best fit when:** Aesthetic appeal, natural look, or compatibility with wooden doors is key.
**6802.2X,6802.9X – Stone**
- **Defining trait:** Made from natural stone like granite or marble; heavy and durable.
- **Typical examples:** High-end commercial entrances, luxury homes.
- **Best fit when:** Longevity, high durability, or architectural elegance is required.
**6810.99 – Concrete/Artificial Stone**
- **Defining trait:** Cast or molded from cement-based materials; strong and weather-resistant.
- **Typical examples:** Industrial door thresholds, outdoor entrances.
- **Best fit when:** Heavy-duty use, outdoor exposure, or structural strength is critical.
**6811.89 – Asbestos/Cement Fiber**
- **Defining trait:** Made from cement with fibrous reinforcement; now largely obsolete due to health risks.
- **Typical examples:** Older buildings, legacy installations (not recommended today).
- **Best fit when:** Identifying vintage or outdated infrastructure.
**7308.30 – Iron/Steel**
- **Defining trait:** Metal construction with high strength and rigidity.
- **Typical examples:** Industrial doors, fire-rated thresholds.
- **Best fit when:** Security, load-bearing capacity, or fire resistance is essential.
**7508 – Nickel**
- **Defining trait:** Rare; used in specialized, corrosion-resistant applications.
- **Typical examples:** High-end marine or chemical environments.
- **Best fit when:** Extreme corrosion resistance needed (very niche).
**7610.10 – Aluminium**
- **Defining trait:** Lightweight, corrosion-resistant metal with modern finish options.
- **Typical examples:** Commercial buildings, modern homes, accessible entrances.
- **Best fit when:** Lightweight, durable, and sleek appearance is desired.
## Key differences
| Material | Weight | Durability | Weather Resistance | Common Use Case |
|----------------|----------|------------|--------------------|--------------------------|
| Plastic | Light | Low–Medium | Good | Residential, low-cost |
| Wood | Medium | Medium | Fair (needs treatment) | Traditional interiors |
| Stone | Heavy | Very High | Excellent | Luxury, high-traffic |
| Concrete | Heavy | Very High | Excellent | Industrial, outdoor |
| Asbestos Cement| Heavy | High | Good | Obsolete/legacy only |
| Iron/Steel | Heavy | Very High | Good (rust-prone) | Security, fire-rated |
| Nickel | Medium | Extremely High | Excellent | Specialized environments |
| Aluminium | Light | High | Excellent | Modern, accessible design|
## How to choose
- Is it made of metal? → Check 7308.30, 7508, 7610.10
- Is it a natural material (wood or stone)? → Check 4418.1X/2X or 6802.2X/9X
- Is it concrete-like or cast? → 6810.99
- Is it plastic or flexible? → 3925.20
- Is it old or from a legacy system? → 6811.89 (use with caution)
## Overlaps & pitfalls
- **Plastic vs. concrete:** Both can be used in residential settings; distinguish by weight and material feel.
- **Aluminium vs. steel:** Both metal—choose based on corrosion resistance and weight needs.
- **Asbestos cement** is outdated and hazardous; avoid unless identifying old installations.
- No clear priority: choose based on the product’s **main function or defining feature** (e.g., durability, appearance, environment)