The invention relates to an annular disc of bent sheet material (21) with at least one junction at which the annulus is closed. Furthermore, a method for producing an annular disc is disclosed, comprising the steps of: (a) providing a sheet material; (b) bending the sheet material into an annular disc; (c) severing the sheet material, so that an annular disc with a junction at which the annulus is open is provided; (d) closing the junction, so that an annular disc with a junction at which the annulus is closed is provided. A description is given of a method for producing an annular disc comprising the steps of: (i) providing a sheet material; (ii) bending the sheet material into a first part of an annular disc; (iii) severing the sheet material, so that a first part of an annular disc is provided; (iv) repeating steps (i), (ii) and (iii) at least once, so that at least one further part of the annular disc is provided; and (v) connecting the first part and the further parts of the annular disc, so that an annular disc with at least two junctions at which the annulus is closed is provided.