Stopper rod having an elongated body of refractory material, a passageway extending longitudinally in the body from an end thereof which is uppermost in use, a carrier rod having a part fixedly received in the passageway and a further part outside of the passageway for attachment to a lifting device for the stopper rod. The passageway has an enlarged part which defines a sealing surface spaced from the end of the body, an insert around the carrier rod having at least a part thereof received in the enlarged part, a retention element on the carrier rod, and an expandable element disposed between the insert and the retention element. The material of the insert has a co-efficient of thermal expansion no greater than that of the carrier rod. Expansion of the expandable element, in use, is greater than that of the carrier rod.