Isahani yicyuma ni isahani yicyuma isukuye hamwe nicyuma gishongeshejwe hanyuma ugakanda nyuma yo gukonjesha. Ikozwe mu isahani iringaniye cyangwa umurongo wibyuma, ushobora guca mu buryo butaziguye mu buryo bwurukiramende. Ibyapa byicyuma bigabanijwe ukurikije ubunini.Icyuma cyoroshye cyane kiri munsi ya 4mm (icyoroshye cyane ni 0.2mm), icyuma kibyibushye ni 4 ~ 60mm, naho icyuma cyinshi cyibyuma ni 60 ~ 115mm. Ubugari bw'urupapuro ni 500 ~ 1500 mm;Ubugari bwubugari ni 600 ~ 3000 mm.Isahani ntoya igabanijwemo ibyuma bisanzwe, ibyuma byujuje ubuziranenge, ibyuma bivanze, ibyuma byamasoko, ibyuma bitagira umwanda, ibyuma byuma, ibyuma birwanya ubushyuhe, bitwaje ibyuma, ibyuma bya silikoni hamwe n’ibyuma byoroheje byoroheje;Ukurikije ubuhanga bw'umwuga, hari isahani ya peteroli, isahani ya emam, isahani itagira amasasu, nibindi;Ukurikije igifuniko cyo hejuru, hari urupapuro rwometseho, urupapuro rwometseho amabati, urupapuro rwometseho isahani, icyuma cya plastiki gikomatanya, nibindi.