a mold for producing a floor made from a polymer material for a motor vehicle , comprising at least one metal insert in the form of sheet metal that is partially overmolded , i . e . having a portion intended to be covered with polymer material and a portion intended to not be covered in this way , the mold comprising a die and a punch defining a cavity , the cavity comprising a location intended to receive the portion of a metal insert intended to be covered with polymer material , wherein the mold , in this location of the cavity , comprises gadroons on the die and on the punch , the gadroons having a thickness that is greater than a predefined minimum thickness . the invention also concerns a floor obtained by this method .