Stam achieved the greatest possible reduction with the cantilever chair S 43 by combining the tubular steel frame with molded wood elements for seat and backrest. The pure, restrained form of this cantilever chair makes it an exemplary design in the spirit of modernism. Today, Thonet owns the artistic copyright for the strictly cubic chair without back legs.

https://www.brandnewoffice.be/nl/thonet-s43-f-stoel-met-armleuning.html