Bell Brothers (Manchester) Ltd were makers of high and low pressure filters for steam boilers, bleachers, and dyers. The parent company was based in Ravensthorpe, West Yorkshire. The company's main business was in the manufacture of water filtration equipment, although during the First World War the Yorkshire factory also manufactured motor vehicle chassis, engines and wheels. Bell Brothers (Manchester) Ltd was originally based on Corporation Street in Manchester. In the 1920s, Bell Brothers bought the water filtration business form Mather & Platt, who then moved the expanded business to the former Denton Tramway Depot building. Bell Brothers renamed the site Calder Iron Works. The company licensed their patent high pressure water filters to W. T. Glover & Co. of Trafford Park, who were the sole manufacturers of Bell's Patent high pressure filters. Bell Brothers were taken over by Paterson Ltd in around 1969. The successor company, Paterson Candy International, closed the Denton site in 1974/5.