# Square steel tube (metalon)

> Component kind `steel-tube-square` (category `static`, DSL name `steelTubeSquare`, API v1)

Hollow square-section steel profile — the primary structural member for benches and frames. Runs along its local Z axis; rotate it to stand or lie as needed.

## Parameters

- **`width`** — Outer side of the square section (mm). Commercial sizes: 20, 25, 30, 40, 50.
- **`wallThickness`** — Wall thickness (mm), 0.9–3 for common metalon.
- **`length`** — Length along the local Z axis (mm).

## Parameters schema

| Parameter | Type | Default | Constraints |
| --- | --- | --- | --- |
| `width` | Number | 50 | min: 10 |
| `wallThickness` | Number | 2 | min: 0.9 |
| `length` | Number | 889 | min: 10 |
| `color` | String | — |  |

## Ports

| Port | Type | Description |
| --- | --- | --- |
| `body` | `rigid` | Rigid structural port. Weld or rest other parts against it; carries no motion. |

## Example

```
statics.steelTubeSquare({
  id: 'leg_fl', width: 50, wallThickness: 2, length: 889,
  transform: { position: [50, 444.5, 50], rotation: [-90, 0, 0] },
});
```