Abstract: The invention relates to the continuous casting of metals into moulds with movable walls. According to the method of producing metal filament, a fraction of molten metal is continuously fed onto an additional chill surface which is contiguous to a main chill surface and displaces relative thereto so that an additional metal filament is formed on the additional chill surface before being separated from this surface and coiled. The apparatus materializing the method incorporates a means (1) of forming metal filament an additional closed chill surface (4) whereof is coupled to an individual drive (9) and to a means (31) of coiling the additional metal filament (32) and is located next to and in contact with the main closed chill surface (2). A feeder (15) is disposed above a zone of contact between the main and additional chill surfaces.