# Hex bolt (metric)

> Component kind `bolt` (category `static`, DSL name `bolt`, API v1)

Simplified metric hex bolt: hex head plus plain shank (no thread modeled). Runs along local Z, head at the +Z end. For fastened joints and the BOM.

## Parameters

- **`diameter`** — Metric diameter enum: M5, M6, M8, M10 or M12.
- **`length`** — Shank length under the head (mm).

## Parameters schema

| Parameter | Type | Default | Constraints |
| --- | --- | --- | --- |
| `diameter` | String | M8 | allowed: M5, M6, M8, M10, M12 |
| `length` | Number | 40 | min: 6 |
| `color` | String | — |  |

## Ports

| Port | Type | Description |
| --- | --- | --- |
| `body` | `rigid` | Rigid port. Placed at a joint; carries no motion. |

## Example

```
statics.bolt({
  id: 'b1', diameter: 'M8', length: 40,
});
```