## Common ground
All options are types of weighing boats—small, flat containers used to hold samples during precise weighing.
## Options at a glance
**3926.90 – Plastic**
- **Defining trait:** Made from plastic, typically lightweight and disposable.
- **Typical examples:** Polypropylene or polystyrene lab trays.
- **Best fit when:** Used for single-use, non-corrosive samples; cost-effective and easy to discard.
**6903 – Refractory ceramic**
- **Defining trait:** Made from heat-resistant ceramic, suitable for high-temperature environments.
- **Typical examples:** Crucibles or trays used in furnace operations.
- **Best fit when:** Required for heating, calcination, or handling molten materials.
**6909.1X – Ceramic**
- **Defining trait:** General ceramic material, often non-refractory; more fragile than refractory types.
- **Typical examples:** Porcelain dishes used in standard lab weighing.
- **Best fit when:** Used for routine, low-heat weighing of chemicals or solids.
**7017 – Glass**
- **Defining trait:** Made from glass, chemically inert and reusable.
- **Typical examples:** Beakers or watch glasses used as weighing vessels.
- **Best fit when:** Need high chemical resistance or precision; often used with sensitive balances.
## Key differences
| Feature | Plastic (3926.90) | Refractory Ceramic (6903) | Ceramic (6909.1X) | Glass (7017) |
|--------------------|-------------------|----------------------------|-------------------|--------------|
| Heat resistance | Low | Very high | Moderate | Moderate |
| Chemical resistance| Good | Excellent | Good | Excellent |
| Reusability | Usually disposable| High | Medium | High |
| Fragility | Low | Low | High | High |
## How to choose
- Is the boat used at high temperatures (e.g., in a furnace)? → 6903
- Does it need to resist strong acids/bases or be reused? → 7017
- Is it for single-use, lightweight, low-cost applications? → 3926.90
- Is it used at room temperature with moderate chemical exposure? → 6909.1X
## Overlaps & pitfalls
- Glass and ceramic can both be chemically inert; choose glass for transparency or precision, ceramic for durability in non-heat settings.
- Refractory ceramic (6903) is a subset of ceramic—do not confuse with general ceramic (6909.1X).
- Plastic may degrade under heat or strong solvents—avoid if sample conditions are harsh.
- No clear priority: choose based on the **main function** (e.g., heat resistance vs. chemical resistance vs. disposability)