Aluminum Helicoid Staircase, Model M400, by Roger Tallon

The Aluminum Helicoid Staircase, Model M400, designed by Roger Tallon between 1964 and 1966 for Galerie Lacloche in Paris, is an iconic example of French Post-War industrial design. Part of Tallon’s celebrated modular M400 series, it is distinguished by its ingenious demountable construction and sculptural spiral form.

Individually cast and polished aluminum steps are arranged around a central steel column, secured with screws and finished with black, non-slip rubber treads. Two-centimeter aluminum spacer rings allow the height to be precisely adjusted. Typically configured with 13 steps, original examples measure approximately 139–148 inches high, with a footprint of approximately 42 × 42 inches, although dimensions varied according to their architectural application. An example of the Helicoid Staircase is held in the permanent design collection of the Museum of Modern Art (MoMA) in New York.

Dimensions: W:42”D:42”H:139”