## Common ground
All options refer to wire binding spines used to hold pages together in books or documents.
## Options at a glance
**3926.10 – Made of plastic material**
- **Defining trait:** Constructed primarily from plastic, typically lightweight and flexible.
- **Typical examples:** Plastic coil spines, spiral binders with thermoplastic coils.
- **Best fit when:** The spine is visibly made of a molded or extruded plastic material, often colored or transparent.
**8305.90 – Made of base metal**
- **Defining trait:** Constructed from non-precious metals like steel or aluminum, usually rigid and durable.
- **Typical examples:** Metal spiral binders (e.g., steel coil), wire-bound spines with metallic cores.
- **Best fit when:** The spine is metallic, has a shiny or solid appearance, and feels heavy or stiff.
## Key differences
| Feature | 3926.10 (Plastic) | 8305.90 (Base Metal) |
|------------------|--------------------------|----------------------------|
| Material | Plastic (e.g., PVC, PP) | Steel, aluminum, etc. |
| Weight | Light | Heavy |
| Flexibility | Flexible | Rigid or semi-rigid |
| Common use | Office, school binders | Professional, long-term use|
## How to choose
- Is the spine made of a molded or extruded plastic? → 3926.10
- Does it feel heavy and metallic? → 8305.90
## Overlaps & pitfalls
A product may combine both materials (e.g., metal coil with plastic coating), but the primary material determines classification. If unclear, prioritize the dominant structural material. The defining trait is material composition—plastic vs. base metal—so choose based on what forms the spine’s core structure