For eliminating the burrs which form on moulded, or injected products, the moulding device and, in particular, the tyre vulcanizing mould is provided with a plastically and elastically deformable portion (13) on the coupling surface existing between the corresponding elements; so much so that the reciprocal coupling, between the facing surfaces, is not simultaneous, but involves a portion of surface having an amplitude that increases in its size, during the shutting movement of the mould.