## Common ground
All options are types of uninsulated electrical conduit tubing used to protect and route electrical wires.
## Options at a glance
**3926.90 – Made of plastic material**
- **Defining trait:** Constructed from non-metallic, typically thermoplastic materials like PVC or HDPE.
- **Typical examples:** PVC electrical conduit, flexible PVC tubing, rigid polyethylene conduit.
- **Best fit when:** Used in corrosive environments, indoor installations, or where electrical insulation is needed without metal conductivity.
**6906.00 – Made of ceramic**
- **Defining trait:** Manufactured from fired clay or similar inorganic non-metallic materials; highly heat and corrosion resistant.
- **Typical examples:** Ceramic conduit for high-temperature industrial settings, vintage or specialty electrical systems.
- **Best fit when:** Required in extreme heat environments (e.g., near furnaces) or where fire resistance is critical.
**7306.30 – Made of iron or steel**
- **Defining trait:** Constructed from ferrous metals; offers high mechanical strength and durability.
- **Typical examples:** Galvanized steel conduit, rigid metal conduit (RMC), threaded steel tubing.
- **Best fit when:** Used in industrial, commercial, or high-impact environments needing robust protection and grounding.
## Key differences
| Feature | 3926.90 (Plastic) | 6906.00 (Ceramic) | 7306.30 (Steel) |
|---------------------|-------------------|------------------|-----------------|
| Material type | Thermoplastic | Fired clay | Ferrous metal |
| Corrosion resistance| High | Very high | Moderate (if uncoated) |
| Mechanical strength | Low to medium | Low | Very high |
| Electrical insulation| Yes | Yes | No (conductive) |
## How to choose
- Is the conduit made of plastic? → 3926.90
- Is it made of fired clay or ceramic? → 6906.00
- Is it made of steel or iron? → 7306.30
## Overlaps & pitfalls
A product could be mistaken for multiple types if material is unclear (e.g., coated metal vs. plastic). Ceramic and plastic both insulate, but ceramic is brittle and not flexible. Steel conducts electricity—this matters for grounding. If the product’s **main function** is mechanical protection in harsh settings, steel wins; if insulation or corrosion resistance is key, choose plastic or ceramic. No priority rule is implied—use the dominant material property to decide