Abstract: A device for regulating the thickness of a metal deposit formed on a strip emerging from a galvanization bath, comprising at least one nozzle for blowing air provided between the opposite, narrowly spaced ends of two jars. The air knife forming slot is delimited by two flat, parallel faces defining the direction of the air blade, one of these faces being provided on a deformable lip extending inside a hollow provided at the end of a first jaw and being slidable along a flat retaining face substantially perpendicular to the direction of the air knife and deforming the flat face by the action of an arrangement to adjust the width of the slot.