Shoko rokuti kukuruunda (wear down by friction, abrasive) rinotaura kukuzvuka kana kupfukunyuka kunoita zvinhu kana zvichikweshana paine rudzindi pakati pazvo. Sokuti kana simbi dziiri painjini dzichifamba panofanirwa kuva nemafuta kana girizi pakati padzo kuti dzisakuzvuka. Chinhu chakamanzika chisina kuita mburuzvira chinonzi chakakwakwashara. Kukukwakwashara kunoita chinhu chimare chichikuzvura zvimwe zviri nyore.