## Common ground
All options are high pressure cylinders categorized by their primary material.
## Options at a glance
**3925.10 – Plastic**
- **Defining trait:** Made from polymer-based plastic, typically for low-to-medium pressure and lightweight use.
- **Typical examples:** Portable gas cylinders for camping, small medical oxygen units.
- **Best fit when:** Weight, corrosion resistance, or cost are priorities; pressure below 200 bar.
**7311.00 – Iron or Steel**
- **Defining trait:** High strength and durability; standard for high-pressure industrial gas storage.
- **Typical examples:** Oxygen tanks for welding, compressed air cylinders.
- **Best fit when:** Maximum pressure (300+ bar), rugged use, or long-term reliability needed.
**7419 – Copper**
- **Defining trait:** Non-sparking and corrosion-resistant; used in sensitive or explosive environments.
- **Typical examples:** Cylinders for acetylene (in specific mixtures), laboratory gases.
- **Best fit when:** Safety in flammable or reactive gas applications is critical.
**7508.90 – Nickel**
- **Defining trait:** Exceptional corrosion and heat resistance; used in extreme environments.
- **Typical examples:** Aerospace, chemical processing, high-purity gas systems.
- **Best fit when:** Exposure to aggressive chemicals or high temperatures.
**7613.00 – Aluminium**
- **Defining trait:** Lightweight with good strength-to-weight ratio; common in portable applications.
- **Typical examples:** SCUBA tanks, mobile gas supplies.
- **Best fit when:** Portability and ease of handling are key.
**7806.00 – Lead**
- **Defining trait:** Very dense but soft and low-strength; not suitable for pressure containment.
- **Typical examples:** Not used for high-pressure cylinders (misleading entry).
- **Best fit when:** None — lead is unsuitable for pressurized containers due to material weakness.
**7907.00 – Zinc**
- **Defining trait:** Low strength and poor corrosion resistance; not used in pressure vessels.
- **Typical examples:** Not applicable for high-pressure cylinders.
- **Best fit when:** None — zinc is unsuitable for pressurized applications.
**8007.00 – Tin**
- **Defining trait:** Soft, low-melting; not suitable for structural or pressure-bearing use.
- **Typical examples:** Not used in high-pressure cylinders.
- **Best fit when:** None — tin is inappropriate for pressure vessels.
**8101.99 – Tungsten**
- **Defining trait:** Extremely dense and strong, but very expensive and hard to process.
- **Typical examples:** Rare, specialized high-performance applications (e.g., research).
- **Best fit when:** Extreme strength or density required, budget is not a constraint.
**8104 – Magnesium**
- **Defining trait:** Lightest metal; flammable when powdered or in thin sections.
- **Typical examples:** Experimental or niche applications (e.g., aerospace prototypes).
- **Best fit when:** Weight reduction is critical and fire risk is managed.
## Key differences
| Material | Strength | Weight | Corrosion Resistance | Safety (Sparks/Flammability) |
|--------------|----------|--------|------------------------|-------------------------------|
| Plastic | Low | Very Light | High | Safe |
| Steel | Very High| Heavy | Moderate | Safe |
| Copper | Medium | Medium | High | Non-sparking |
| Nickel | High | Medium | Very High | Safe |
| Aluminium | High | Light | Good | Safe (if handled properly) |
| Lead | Very Low | Heavy | Poor | Unsafe (toxic, weak) |
| Zinc | Low | Medium | Poor | Unsafe (reactive) |
| Tin | Very Low | Medium | Poor | Unsafe |
| Tungsten | Extreme | Very Heavy | High | Safe |
| Magnesium | Medium | Very Light | Poor (flammable) | Risk of ignition |
## How to choose
- Is the cylinder for high pressure (≥200 bar)? → No: Plastic, Lead, Zinc, Tin
- Is weight a major concern? → Yes: Aluminium, Magnesium, Plastic
- Is safety in flammable environments critical? → Yes: Copper, Aluminium
- Is corrosion resistance essential? → Yes: Nickel, Copper, Aluminium
- Is cost or standard use the priority? → Yes: Steel
## Overlaps & pitfalls
- **Plastic** may be used for low-pressure applications but not high pressure.
- **Lead, Zinc, Tin** are inappropriate for high-pressure cylinders — likely misclassified.
- **Magnesium** is flammable; only suitable in controlled environments.
- **Tungsten** is overkill for most uses; only for extreme cases.
- **No single option dominates** — choose based on the product’s MAIN function and operating conditions