## Common ground
All are containers used for measuring or dispensing liquids, typically with calibrated markings.
## Options at a glance
**3926.90 – Plastic**
- **Defining trait:** Made from plastic, offering lightweight, impact-resistant, and low-cost construction.
- **Typical examples:** Lab beakers, disposable measuring cylinders.
- **Best fit when:** Durability against drops, low cost, or single-use applications are priorities.
**6903 – Refractory ceramic**
- **Defining trait:** Designed to withstand very high temperatures without degrading.
- **Typical examples:** Crucibles for melting metals, high-temp lab vessels.
- **Best fit when:** The vessel must endure extreme heat or chemical exposure in industrial settings.
**6909.1X – Ceramic**
- **Defining trait:** Made from standard ceramic (non-refractory), typically used for general-purpose or decorative use.
- **Typical examples:** Pottery measuring jugs, traditional labware.
- **Best fit when:** Moderate heat resistance and aesthetic appeal are needed, but not extreme conditions.
**7017 – Glass**
- **Defining trait:** Transparent, chemically inert, and suitable for precise measurements.
- **Typical examples:** Volumetric flasks, burettes, graduated cylinders in labs.
- **Best fit when:** Accuracy, clarity, and resistance to chemicals are essential.
## Key differences
| Feature | Plastic | Refractory ceramic | Ceramic | Glass |
|---------------------|---------------|--------------------|---------------|---------------|
| Heat resistance | Low | Very high | Moderate | Moderate |
| Chemical resistance | Varies | High | Medium | Very high |
| Transparency | Opaque/Translucent | Opaque | Opaque | Transparent |
| Precision use | Low–Medium | Low | Medium | High |
## How to choose
- Is the vessel used in high-heat environments (e.g., melting, firing)? → 6903
- Does it need to be transparent for accurate reading? → 7017
- Is it intended for single-use or low-cost applications? → 3926.90
- Is it decorative or used in moderate conditions without strict precision? → 6909.1X
## Overlaps & pitfalls
- A ceramic vessel may be mistaken for refractory if heat-resistant, but only 6903 is designed for extreme heat.
- Glass and plastic can both be used in labs, but glass wins for precision; plastic for safety or disposability.
- If unsure, prioritize the **main function**: measurement accuracy → glass; high-temp use → refractory ceramic