By Huu Khanh Nguyen · Updated October 28, 2026 · stair, flight
A steep stair flight whose cut-corner plate treads alternate from the left and the right of a central stringer.
| Name | Default | Unit |
|---|---|---|
| Number of risers (the flight has risers - 1 treads, the last riser meets the upper level) | 8 | |
| Riser height, vertical distance between two successive treads | 173.7 | mm |
| Going, horizontal distance between the noses of two successive treads (y) | 117.2 | mm |
| Clear width between the handrails (x), the two treads and the stringer fill it | 508 | mm |
| Tread depth, front to rear (y) | 266.7 | mm |
| Tread sheet thickness (z) | 2.278 | mm |
| Centre stringer U section, side across the flight (x) | 50.8 | mm |
| Finish of the flight's own parts | white | |
| Slope of the flight from the horizontal, degrees (OSHA and IBC 50 to 70) | Math.atan(rise / going) * 180 / Math.PI | ° |
| Width of the box (x) | risers > 2 ? width : width / 2 + stringerWidth / 2 | mm |
| Depth of the box (y) | Math.max((((risers * rise) - ((rise - thickness))) / (rise / going)), (risers - 2) * going + treadDepth) - (-((rise - thickness) + (44.45 * Math.sqrt(1 + (rise / going) * (rise / going)))) / (rise / going)) | mm |
| Height of the upper level above the lower floor (z) | (risers * rise) | mm |