Plate Being Rolled on the 206” Mill – The onset of war led to an increasing demand for wider steel plates.  In 1917, Lukens planned and built the 204” Mill, which rolled its first plates in May 1918.  The mill was enlarged to 206 inches in 1919, giving Lukens the World’s Largest Plate Mill for more than forty years.  Today the Coatesville site continues to use the 206” Mill, still one of the world’s widest plate mills.