Alloy steel - Na ndabere nke ígwè carbon nkịtị, iji mee ka arụ ọrụ nke ígwè dịkwuo mma, a na-etinye otu ihe ma ọ bụ karịa alloying ọcha na nchara n'oge agbaze. Dị ka dị iche iche kwukwara ọcha, na-ewere kwesịrị ekwesị nhazi technology, nwere ike ime ka ígwè nweta elu n'ibu Njirimara, hardenability, tempering kwụsie ike, ike.