Waxaa jira noocyo badan oo kala duwan oo ka mid ah alaabooyinka usheeda dhexe, oo ay ku jiraan kuwa toosan, cylindrical, spiral, convex, iyo shaft concave. Qaabkooda iyo cabbirkoodu waxay ku xiran yihiin codsiga gaarka ah iyo shaqada la rabo. Alaabta shafka ah ayaa inta badan si sax ah loo farsameeyaa si loo hubiyo simanaanta dusha sare iyo saxnaanta cabbirka, taas oo u oggolaanaysa inay si deggan ugu shaqeeyaan xawaare sare oo wareeg ah ama culaysyo sarreeya.