Cantilevered wooden staircase, has multiple risers connected to steps, two groups of threaded rods anchored in risers and arranged against wall, where riser is designed in form of tongue-groove joint

摘要

The staircase (1) has multiple risers (4) connected to steps (3). Two groups of threaded rods (5, 6) are anchored in the risers, and are arranged against a wall (2), where the diameter of each threaded rod is 8-12 mm. The riser is designed in the form of a tongue-groove joint (9).