## Common ground
All options refer to iron or steel wire, differentiated by their material composition.
## Options at a glance
**7217 – Iron or non-alloy steel**
- **Defining trait:** Made from plain iron or carbon steel without significant alloying elements.
- **Typical examples:** Fence wire, binding wire, spring wire (low-carbon).
- **Best fit when:** The wire is not corrosion-resistant and lacks visible alloying metals like chromium or nickel.
**7223.00 – Stainless steel**
- **Defining trait:** Contains at least 10.5% chromium for corrosion resistance; typically includes nickel (e.g., 304/316 grades).
- **Typical examples:** Kitchen sink drain strainers, medical instruments, outdoor architectural wire.
- **Best fit when:** The wire resists rust and is used in wet or harsh environments.
**7229 – Other alloy steel**
- **Defining trait:** Contains significant alloying elements (e.g., manganese, chromium, molybdenum) beyond stainless steel, for strength or heat resistance.
- **Typical examples:** High-strength cables, engine valve springs, tool wire.
- **Best fit when:** The wire is hardened or designed for high stress/temperature, but not stainless.
## Key differences
| Feature | 7217 (Non-alloy) | 7223.00 (Stainless) | 7229 (Other alloy) |
|---------------------|------------------|----------------------|--------------------|
| Corrosion resistance| Low | High | Medium to high |
| Alloying elements | None or minimal | Chromium ≥10.5% | Manganese, Mo, etc.|
| Typical use | General purpose | Hygienic, outdoor | High-performance |
## How to choose
- Is the wire visibly shiny and rust-resistant? → 7223.00
- Does it look like regular steel and show signs of rust? → 7217
- Is it used in high-stress or high-heat applications (e.g., machinery)? → 7229
## Overlaps & pitfalls
Stainless steel (7223.00) may also be considered an alloy steel, but its chromium content makes it distinct. If a wire is stainless, it should go in 7223.00 even if it has other alloys. The main function determines the category: corrosion resistance → 7223.00; strength/heat resistance without rust resistance → 7229. Do not prioritize based on alloy content alone—use the primary purpose or material property