Alloy nchara bụ ígwè nke a na-ejigide ọtụtụ ihe na ngụkọta dị iche iche n'agbata 1.0% na 50% site na ibu iji meziwanye akụrụngwa ya. A na-agbaji Steals steels n'ime otu abụọ: ala dị ala na steellis steels. Ihe dị iche n'etiti mmadụ abụọ ahụ. Smith na Hahemi Kọwaa ihe dị iche na 4.0%, ebe Degarmo, et al., Kọwaa ya na 8.0%. [1] Ọtụtụ mgbe, ahịrịokwu "Alloy steel" na-ezo aka na Lower Steel.
Igwe anaghị agba nchara bụ alloy nke iron na-eguzogide na-eguzogide. O nwere opekata mpe 11% 12% ma nwee ike ịnwe ihe dị ka carbon, ndị ọzọ na-abụghị na ọla kọpa nweta ihe ndị ọzọ achọrọ. Na-egbochi mgbochi na corrosion si na-esite na Chromium, nke na-eme ihe nkiri na-enweghị ike nke nwere ike ichebe ihe na ịgwọ onwe ya n'anya oxygen.