Agaçdan ýasalan gural materiallary uglerod gurallary polat, garyndy gural polat, ýokary tizlikli polat, sementlenen karbid, kub bor nitridi, sintetik göwher we ş.m., uglerod gural poladyndan sementlenen karbidiň ösüşine çenli gural materiallary bolup, kubda tehnologiki ösüşleri görkezýär. ..
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