Abstract: The invention discloses a marking device for a mould having a housing in a wall. The device includes a threaded cylindrical body and a circular head of a diameter about equal to the diameter of the housing. A face of the head opposite to the body includes structure that turns the head and a marking distinct from the structure and independent from the position of the structure. A length of the body and head are less than the length of the housing in the mould in order that the face with the marking lies flush with the internal face of the wall of the mould when the device is in the housing.

Abstract: The invention discloses a marking device comprising: a head (8) to flush with the internal surface of a mold (6), the side (14) of the head facing inside the mold having a mark and means (16) for driving the head in rotation; a threaded cylindrical body (10) forming a single piece with the head (8) of the device; optionally a threaded socket (2) with an external diameter corresponding to the external diameter of the head (8) of the device and its internal screw thread corresponding to the threading of its body, such that when the body is screwed in the socket, the resulting assembly has a cylindrical circular shape.