Ọgwụgwọ dị n'elu: phosphate ojii/zinc na-acha anụnụ anụnụ / zinc plating
Ihe onwunwe: carbon ígwè
Na-eji: Kwesịrị ekwesị maka bọọdụ gypsum, keel osisi, njikọ mgbidi, mgbidi nkebi dị fechaa na nrụnye n'uko ụlọ.