Iyo elastic cylindrical pini, inozivikanwawo sepini yechitubu, ikona isina musoro isina mhango ine axial slot uye chamfer kumigumo yese, iyo inoshandiswa kuisa, kubatanidza uye kugadzirisa pakati pezvikamu.Izvo zvinodikanwa kuve neyakanaka elasticity uye shear kuramba, uye dhayamita yekunze yerudzi urwu rwepini yakakura zvishoma pane aperture yegungano.