Quarter Circle Starting Step
By Huu Khanh Nguyen · Updated October 28, 2026 · stair, starting-step
The first step of a flight with one or both front corners rounded, tread and riser in one piece.
Parameters
| Name | Default | Unit |
|---|---|---|
| Flight width across the step (x) | 1219 | mm |
| Going, nosing to nosing of the flight (y); the step is going + overhang deep | 292 | mm |
| Rise of the step, floor to top surface (z) | 203 | mm |
| Tread thickness (z, from the top surface down) | 25 | mm |
| Rounded end of a single end step | right | |
| Ends | single | |
| Nosing overhang beyond the riser line (y) | 28.6 | mm |
| Riser thickness | 19 | mm |
| Finish | white | |
| Radius of the rounded front corner (plan) | 178 | mm |
| End projection past the flight width (x) | 0 | mm |