A fully researched heritage article documenting the history of Thomas & Clement Ltd, ironfounders and engineers, established at the Morfa Foundry, Machynis, Llanelli in 1874 by Henry Thomas and John Clement. The article covers the company's founding, incorporation in 1907, its role in supplying the South Wales tinplate and colliery industries, its wartime contribution including the manufacture of Mulberry Harbour Bridge sections used in the D-Day Normandy landings of 1944, its merger with the Glanmor Foundry Company to form Glanmorfa Foundry Ltd in 1939, and the closure of the foundry in 1954. Includes archive sources, image acknowledgements, and a full summary and legacy assessment. Research prompted by the discovery of an original brass company plaque. Article includes an aerial photograph of the Morfa Foundry site sourced from People's Collection Wales.