Q245b nicyuma gisanzwe cyubaka karubone gifite ingufu za MPa 245, kikaba icyuma cyica igice.
Ibirimo bya karubone bigera kuri 0,05% kugeza 0,70%, kandi bimwe bishobora kuba hejuru ya 0,90%.Irashobora kugabanywamo ubwoko bubiri: ibyuma bisanzwe byubatswe byubatswe nicyuma cyiza cya karubone.Hano harakoreshwa byinshi kandi byinshi byo gukoresha.Ikoreshwa cyane cyane muri gari ya moshi, ibiraro, hamwe nimishinga itandukanye yubwubatsi kugirango ikore ibyuma bitandukanye bitwara imizigo ihamye, hamwe nibice bya mashini bidafite akamaro bidasaba kuvura ubushyuhe no gusudira muri rusange.