Metalworking is a highly specialised craft amongst the Nagas with all forms of metalworking being produced by men rather than women. The Konyaks and Kalyo-Kengyus are known for producing pieces made from iron, tin or sheet brass that is heated and hammered. The lost wax method of casting usually using brass poured into a stone mould lined with pig fat was another technique that was employed. (see Jacobs, J., The Nagas, Society, Culture and Colonial Encounter, London 1990, p.50).