# Circular Bends

`bend_circular_factory(kcl)` produces constant-radius arc bends. Unlike euler bends, the footprint radius equals the nominal radius (up to DBU rounding). `kf.routing.optical.get_radius` returns DBU, so convert it to µm for comparison. Arguments `width` and `radius` are in **µm**.

```
import kfactory as kf
from kfactory.factories.circular import bend_circular_factory


class LAYER(kf.LayerInfos):
    WG: kf.kdb.LayerInfo = kf.kdb.LayerInfo(1, 0)


pdk = kf.KCLayout("FACTORIES_CIRCULAR_DEMO", infos=LAYER)
L = LAYER()
```

```
bend_circ = bend_circular_factory(pdk)

bc90 = bend_circ(width=0.5, radius=10.0, layer=L.WG)
print("circular bend:", bc90.name)
footprint_radius_um = bc90.kcl.to_um(kf.routing.optical.get_radius(bc90.ports))
print("footprint radius:", footprint_radius_um, "µm (== nominal)")
bc90
```

```
circular bend: bend_circular_CSsym_028523d7_500_R10_A90_AS1
footprint radius: 10.0 µm (== nominal)
```

```

```

## See Also

| Topic | Where |
| --- | --- |
|  |  |