Icyuma cyerekana ni icyuma gifata mbere yo gutunganyirizwa mbere ya polygonal hamwe nu mpande nyinshi zo gukata kumubiri wigikoresho ukoresheje imashini. Iyo gukata guhindutse mugihe cyo gukoresha, ugomba gusa guhanagura clamping yicyuma hanyuma ukerekana indangagaciro cyangwa ugasimbuza icyuma kugirango impande nshya yo gukata yinjira mumurimo wakazi, hanyuma irashobora gukomeza gukoreshwa nyuma yo gufatirwa. Bitewe no gukata cyane hamwe nigihe gito cyo gufashanya cyibikoresho byerekanwa, imikorere myiza iratera imbere, kandi umubiri ukata igikoresho cyerekanwe urashobora kongera gukoreshwa, ukazigama ibyuma ninganda, bityo ubukungu bwabwo bukaba bwiza. Iterambere ryibipapuro byerekana gukata byateje imbere cyane iterambere ryikoranabuhanga ryo guca ibikoresho, kandi muri icyo gihe, umusaruro wihariye kandi usanzwe wogukora ibyuma byerekana ibimenyetso byateje imbere iterambere ryibikorwa byo guca ibyuma.