Abstract: A sealing strip for mounting on a flange, such as surrounding a closable opening in a vehicle body, has a channel-shaped gripping part supporting a softer sealing part against which the closure member for the opening sealingly closes. The gripping part comprises a metal carrier embedded in extruded rubber or plastics material. Where the flange is relatively thick, the gripping part is pre-formed with its channel sides substantially parallel to each other so as firmly to grip the flange. However, where the flange is thinner, one side of the gripping part is moved closer to the other side and the gripping part thus still firmly grips the flange. During manufacture, the gripping part is passed through apparatus which is pre-programmed to adjust the width of the gripping part along the length of the sealing strip, the different configurations being automatically positioned along the length of the sealing strip in correspondence with the known changes in thickness of the flange.