Method for the production and packaging of steel bars or rods and profiles, including the following steps: rolling rods or profiles of indefinite length, scrap separating the rods or profiles, diverting the rods or profiles, cutting said bars or profiles in bar portions (1a, 1b) having at least a first fixed length, changing the speed of the bar portions by means of a speed changing device providing at least two cylinders or rotating drums (8a, 8b), each of the at least two cylinders or rotating drums (8a, 8b) having an outer surface provided with grooves or housings, which during the rotation pass from an upper position wherein the grooves or housings receive the bar portions (1a, 1b), to a lower position, wherein the grooves or housings download the bar portions (1a, 1b), the grooves or housings having a second fixed length, greater than said first fixed length and greater than the commercial length of the bars, the speed changing device being able to handle said bar portions (1a, 1b) at a set speed rate such that said portions can be placed within respective grooves or housings, so that the grooves or housings in the upper position receive relative bar portions (1a, 1b), while the grooves or housings in the lower position download the bar portions (1a, 1b), which have been previously received in the upper position, on at least one cooling plate, wherein each rotating cylinder (8a, 8b) is associated with a different speed changing device, so that said grooves or housings of different rotating cylinders (8a, 8b) receive said bar portions (1a, 1b) at different speeds, depending on the fact that said grooves or housings belong to one first or to at least one second rotating cylinder, and so that said bar portions (1a, 1b) have different stop positions in the relative housings, in a direction perpendicular to the direction of rotation of said cylinders (8a, 8b), characterized in that said bar portions (1a, 1b) have the same positions within said housings, both for said first rotating cylinder and for said second rotating cylinder, so that said bar portions (1a, 1b) are arranged within said grooves or housings of each respective rotating cylinder (8a; 8b) always in the same positions, so that, during the download of the bar portions (1a, 1b) on the at least one cooling plate, the bar portions (1a, 1b) do not overlap each other. rolling rods or profiles of indefinite length, scrap separating the rods or profiles, diverting the rods or profiles, cutting said bars or profiles in bar portions (1a, 1b) having at least a first fixed length, changing the speed of the bar portions by means of a speed changing device providing at least two cylinders or rotating drums (8a, 8b), each of the at least two cylinders or rotating drums (8a, 8b) having an outer surface provided with grooves or housings, which during the rotation pass from an upper position wherein the grooves or housings receive the bar portions (1a, 1b), to a lower position, wherein the grooves or housings download the bar portions (1a, 1b), the grooves or housings having a second fixed length, greater than said first fixed length and greater than the commercial length of the bars, the speed changing device being able to handle said bar portions (1a, 1b) at a set speed rate such that said portions can be placed within respective grooves or housings, so that the grooves or housings in the upper position receive relative bar portions (1a, 1b), while the grooves or housings in the lower position download the bar portions (1a, 1b), which have been previously received in the upper position, on at least one cooling plate, wherein each rotating cylinder (8a, 8b) is associated with a different speed changing device, so that said grooves or housings of different rotating cylinders (8a, 8b) receive said bar portions (1a, 1b) at different speeds, depending on the fact that said grooves or housings belong to one first or to at least one second rotating cylinder, and so that said bar portions (1a, 1b) have different stop positions in the relative housings, in a direction perpendicular to the direction of rotation of said cylinders (8a, 8b), characterized in that said bar portions (1a, 1b) have the same positions within said housings, both for said first rotating cylinder and for said second rotating cylinder, so that said bar portions (1a, 1b) are arranged within said grooves or housings of each respective rotating cylinder (8a; 8b) always in the same positions, so that, during the download of the bar portions (1a, 1b) on the at least one cooling plate, the bar portions (1a, 1b) do not overlap each other.