Roberts, Cadman & Co was founded by Samuel Roberts and George Cadman in 1784. The firm was based on Eyre Street and marked its goods with the symbol of a bell. Roberts, Cadman & Co introduced the technique of manufacturing Old Sheffield Plate goods with silver threaded edges around 1785. This was an important innovation as it masked the copper that would otherwise be visible, giving an object a closer resemblance to solid silver.
The firm was renamed Roberts, Smith & Co in 1826 when a new partner joined the company a few years after George Cadman's death. William Sissons then joined the firm in 1834. After Roberts' retirement in 1848, the company was renamed Smith, Sissons & Company. Smith retired in 1858 and Sissons was joined by his sons, William and George. After this time, the firm is known as W & G Sissons.