When developing his textiles machines, Roberts took as partners Thomas Sharp, an iron merchant, and his brother John Sharp, Robert Chapman, Thomas Jones Wilkinson and James Hill. They formed two firms, Sharp Hill & Co and Roberts, Hills & Co, and in May 1826 these were amalgamated to form Sharp, Roberts & Co. The firm later became well known for making locomotives (described in Sharp, Stewart and Company - Early days). In 1834 Charles Beyer joined the firm and contributed to its success in locomotive building as Roberts soon delegated most of the locomotive design work to Beyer.