By Huu Khanh Nguyen · Updated October 28, 2026 · stair, curved-flight
A stair flight that turns on an arc, its treads carried by one concrete beam winding under the centre line.
| Name | Default | Unit |
|---|---|---|
| Number of risers in the flight (the flight has risers - 1 treads, the upper level is the landing) | 40 | |
| Riser height | 150 | mm |
| Radius of the inner edge of the flight in plan (the well) | 1360 | mm |
| Radial width of the flight | 2000 | mm |
| Total turn of the flight in plan | 360 | ° |
| Direction of climb seen from above | left | |
| Tread thickness passed to the tread (z) | 40 | mm |
| Beam width across the flight (radial) | 500 | mm |
| Beam depth measured vertically | 1500 | mm |
| Finish | white | |
| Plan angle of one step | angle / (risers - 1) | ° |
| Going on the walking line | (innerRadius + Math.min(width / 2, 500)) * stepAngle * (Math.PI / 180) | mm |
| Tread length at the inner edge | innerRadius * stepAngle * (Math.PI / 180) | mm |