A rolling stand for rolling a tube defining a rolling axis, comprising: - a supporting structure, - a roll-holder cartridge configured to go from a working position inside the supporting structure, at the rolling axis, to an extracted position outside the supporting structure with a transverse movement with respect to the rolling axis, - three rolling rolls (2, 2', 2"), each of which having a respective support (6, 6', 6"), arranged in the roll-holder cartridge with respective symmetry axes arranged at 120o with respect to one another, a first roll of said three rolling rolls (2, 2', 2") having the respective symmetry axis arranged horizontally and the respective rotation axis arranged vertically, - at least one hydraulic capsule (4, 4', 4") for each rolling roll, in order to adjust the radial position of the respective rolling roll (2, 2', 2"), fixed to the supporting structure with a respective thrust cylinder, the at least one hydraulic capsule being configured to allow the respective thrust cylinder to cover a sufficient distancing stroke from the rolling axis to allow to clear the path of the roll-holder cartridge between the working position and the extracted position, characterized in that the roll-holder cartridge has two first walls (3', 3") facing each other, each first wall having an opening equal to that of the other wall and defining three branches, wherein a first branch of the opening has elongated shape along the horizontal symmetry axis of the first roll, and wherein a second branch and a third branch have a symmetry axis arranged at a 120° angle with respect to the symmetry axis of the first roll, wherein the first branch is open at an end thereof coinciding with a side of the roll-holder cartridge, wherein the supporting structure has two second walls (13', 13") facing each other and there are three pairs of first axial resting surfaces (7, 7', 8, 8', 9, 9') on the inner surface of each of said two side walls (13', 13"), wherein each pair of first axial resting surfaces, when the cartridge is in said working position, is arranged so as to be in the first, second and third branch of the openings of the first walls (3', 3") of the roll-holder cartridge and facing, along the direction of the rolling axis, to corresponding pairs of second axial resting surfaces (27, 27', 26, 26', 28, 28') integral with the support (6, 6', 6") of the rolling rolls, whereby the rolling forces directed along the rolling axis are directly discharged from the supports (6, 6', 6") to the supporting structure. - a supporting structure, - a roll-holder cartridge configured to go from a working position inside the supporting structure, at the rolling axis, to an extracted position outside the supporting structure with a transverse movement with respect to the rolling axis, - three rolling rolls (2, 2', 2"), each of which having a respective support (6, 6', 6"), arranged in the roll-holder cartridge with respective symmetry axes arranged at 120o with respect to one another, a first roll of said three rolling rolls (2, 2', 2") having the respective symmetry axis arranged horizontally and the respective rotation axis arranged vertically, - at least one hydraulic capsule (4, 4', 4") for each rolling roll, in order to adjust the radial position of the respective rolling roll (2, 2', 2"), fixed to the supporting structure with a respective thrust cylinder, the at least one hydraulic capsule being configured to allow the respective thrust cylinder to cover a sufficient distancing stroke from the rolling axis to allow to clear the path of the roll-holder cartridge between the working position and the extracted position, characterized in that the roll-holder cartridge has two first walls (3', 3") facing each other, each first wall having an opening equal to that of the other wall and defining three branches, wherein a first branch of the opening has elongated shape along the horizontal symmetry axis of the first roll, and wherein a second branch and a third branch have a symmetry axis arranged at a 120° angle with respect to the symmetry axis of the first roll,