Urunigi muri rusange ni icyuma gihuza cyangwa impeta, ikoreshwa cyane mugukwirakwiza no gukurura. Ibintu bimeze nk'urunigi bikoreshwa mu kubuza inzira z'umuhanda (nko ku bwinjiriro bw'imihanda, inzuzi cyangwa ibyambu), iminyururu ikoreshwa mu guhererekanya imashini.

1. Urunigi rurimo ibice bine: urunigi rwohereza; urunigi; gukurura urunigi; urunigi rwihariye.

2. Urukurikirane rwihuza cyangwa imirongo ikozwe mubyuma: ibintu bimeze nkumunyururu bikoreshwa mukubuza inzira zumuhanda (nko kumuryango wumuhanda, uruzi cyangwa icyambu); urunigi rukoreshwa mugukwirakwiza imashini.

3. Iminyururu irashobora kugabanywamo iminyururu ngufi-yerekana neza urunigi; iminyururu ngufi-yerekana neza iminyururu; iminyururu igoramye ingoyi yohereza imirimo iremereye; iminyururu kumashini ya sima n'iminyururu; iminyururu ikomeye.

Imiterere yumurongo wogukwirakwiza igizwe nuruhererekane rwimbere nuruhererekane rwinyuma. Igizwe n'ibice bitanu bito: isahani y'imbere, isahani y'inyuma, isahani, amaboko hamwe na roller. Ubwiza bwurunigi buterwa na pin.

Mu guhererekanya ibikoresho byimashini, ibice byakunze gukoreshwa harimo pulleys, gear, ibikoresho byinyo, rack na pinion, hamwe nimbuto za screw. Binyuze muri ibyo bice byogukwirakwiza, inkomoko yimbaraga na moteri, cyangwa ihuriro hagati yimikorere yombi, byitwa guhuza. Urukurikirane rwibintu bikurikirana bikora ihererekanyabubasha byitwa urunigi.

Urunani rwogukwirakwiza rusanzwe rufite ubwoko bubiri bwokwirakwiza: ubwoko bumwe nuburyo bwogukwirakwiza bufite igipimo cyagenwe cyagenwe nicyerekezo cyogukwirakwiza, nkibikoresho byagenwe byagenwe, inyo ya turbine yinyo, nibindi, byitwa uburyo bwogukwirakwiza ibipimo; ubundi bwoko bushingiye kubisabwa gutunganya Uburyo bwo kohereza bushobora guhindura igipimo cyogukwirakwiza nicyerekezo cyogukwirakwiza, nkuburyo bwo guhinduranya ibikoresho, uburyo bwo kohereza ibikoresho, nibindi byitwa uburyo bwo gusimbuza.