An open hose clamp has a tensioning device in the form of an Oetiker ear 24. The tensioned state is locked by means of toothed regions 15, 23, which engage in one another outside the ear region on the side of the ear 24 facing away from the outer clamp strip end. In the locked state, the ear is free of forces, so that the hose clamp does not lose the clamping function thereof even in the event of damage to the outwardly projecting ear 24.