The metal sheet or one of the metal sheets to align and fix the seal on to a to-be-sealed object with, at least, a folded-over collar (7) in front of it. The layout and dimensions are such that it can be fitted in a corresponding boring (8) in the to-be-sealed object. It may be handled about a cylinder-head seal. The folded-over collar may be fittable in a through-hole opening, for instance a locating hole or a bolting hole. The collar may be fitted in an annular groove (14) upwards, sealing the neighbouring regions of the borings. The collar may be insertable in a locating hole and fixed on the object with the help of a clamping sleeve (13).
