Cov pa roj carbon-graphite yog cov khoom siv nws tus kheej, thiab yog ntau yam khoom siv lub ntsej muag siv nrog mating rings ntawm cov ntaub ntawv nyuaj xws li silicon carbide, alumina, lossis tungsten carbide. Peb cov pa roj carbon monoxide muaj cov yam ntxwv zoo dua qub thiab dav siv tshuaj lom neeg. Forsevere corrodents nrog rau hydrofluoric thiab nitric acids, tshwj xeeb carbongrades muaj.