A carding machine has a number of rollers including a cylinder and having at least one clothed and/or unclothed machine element located opposite the cylinder at a spacing therefrom. The machine may have further elements influencing the carding nip. In order to make possible a carding nip between the cylinder and the clothed and/or unclothed counterpart element that remains constant or virtually constant when heat is generated, the parts influencing the carding nip are so construed that they have thermal expansion characteristics which are such that, when subjected to the heat acting on them in use, the carding nip remains substantially constant.