William Turnbull’s studio at Camden Square, London. Photo: Kim Lim. © Estate of William Turnbull

screwhead (1957), installation view, William Turnbull at Chatsworth, solo exhibition, Chatsworth House and Garden, 2012. © Estate of William Turnbull

Installation view, William Turnbull: Sculpture and Painting, retrospective exhibition, Serpentine, London, 1995. © Estate of William Turnbull

nstallation view, William Turnbull, solo exhibition, Hayward Gallery, 1968. © Estate of William Turnbull