Kooxda jirka ee casriga ah ayaa inta badan ka kooban jidh ahaan, madaxa dhululubo, daboolka madaxalerder, lineyluder line, daboolka dhagaxa weyn iyo daboolka saliidda. Kooxda Jidhku waa taageerada mashiinka, waana saldhiga Golaha ee xijaabka isku xidhka farsamada, qaabka tuubbada iyo qaybaha ugu waaweyn ee nidaamka mashiinka. Madaxa dhululubo ayaa loo isticmaalaa in lagu xidho dusha sare ee dhululubada iyo darbiga dusha sare ee bastooladda. Madaxa dhululubo waxaa lagu dhex tuuraa jaakad biyo ah, god biyo ah, daloolka biyaha, olol dhalaal, god Bolt, Rugta gunta, iwm.