Isifudumezi sombhobho senziwe sisifudumezisi sokuntywiliselwa esigqunywe ligumbi lesitya sesinyithi esichasene nomhlwa.Le casing isetyenziselwa ukugquma ukuthintela ukulahleka kobushushu kwinkqubo yokujikeleza.Ilahleko yobushushu ayisebenzi nje ngokusetyenziswa kwamandla kodwa iya kubangela iindleko zokusebenza ezingeyomfuneko.