Having learnt to weld, in order to create larger scale Mobiles and Stabiles suitable for public display, a swift period of evolution began for Chadwick in the early 50's. As the moving elements gradually fused into welded metal rods and iron, the attitude and energy of his angular sculptures sharpened. Delicate and aggressive, these forms are a haunting synthesis of horns, teeth, spikes and pincer-like legs.

In 1953 Chadwick introduced plaster into his work. The process of welding metal armatures and surfacing them with plaster became the template for creating bronze casts from what became known as working models (see Bronze Works).

In 1962, Chadwick produced his largest Welded Iron work, see 'Two Winged Figures', which went on display at the city of Spoleto, Italy for the 'Festival of Two Worlds' exhibition.

During the winter of 1963, Chadwick was held captive by heavy snow at his home in Gloucestershire. Unable to obtain the materials he was then working with (Iron rods and Stolit), he collected broken machinery about the dilapidated outbuildings. He used this assortment of parts to weld together a unique collection of work, see Transmuter III -1963. Most of these works are now on permanent loan to Nordjyllands Kunstmuseum, Aalborg, Denmark.