Sectional door comprising: - a door leaf composed of panels which are articulated to one another and the end faces of which are arranged in L-shaped guide rails, - a drive shaft which is arranged in the upper part of the door and which lies parallel to the panel planes, is supported by end support brackets (1, 9, 10, 15) and is connected to a drive, and - at least one torsion bar device with torsion springs, wherein: - the torsion springs are pushed onto the drive shaft on the shaft stubs, - the torsion springs are fastened with in each case one of their ends to the drive shaft, - the drive shaft is equipped with cable drums which are fastened to the shaft stubs by means of transition pieces, - the cables are connected to the lower and/or the upper door panel, and - the drive shaft is designed as a hollow-cylindrical shaft, characterized in that: - the drive shaft is formed with in each case one spring groove at the fastening points of the transition pieces for the cable drums, - the centre piece of the drive shaft is designed to be octagonal in cross section and consists of cold-rolled profiled structural steel, - the bending deflection between any two support points of the shaft is at most 1/600 of the length of the torsion bar device, - the octagonal shaft piece is of multi-part design over the length, wherein it is provided with a shaft coupling, - this shaft coupling is formed from two or four sheet metal sections which are screwed to one another at the flange points, and - at least one of the pieces of each of these sheet metal sections that adjoins the drive shaft is screwed to the drive shaft in the region between the flanges. - a door leaf composed of panels which are articulated to one another and the end faces of which are arranged in L-shaped guide rails, - a drive shaft which is arranged in the upper part of the door and which lies parallel to the panel planes, is supported by end support brackets (1, 9, 10, 15) and is connected to a drive, and - at least one torsion bar device with torsion springs, wherein: - the torsion springs are pushed onto the drive shaft on the shaft stubs, - the torsion springs are fastened with in each case one of their ends to the drive shaft, - the drive shaft is equipped with cable drums which are fastened to the shaft stubs by means of transition pieces, - the cables are connected to the lower and/or the upper door panel, and - the drive shaft is designed as a hollow-cylindrical shaft, characterized in that: - the drive shaft is formed with in each case one spring groove at the fastening points of the transition pieces for the cable drums, - the centre piece of the drive shaft is designed to be octagonal in cross section and consists of cold-rolled profiled structural steel, - the bending deflection between any two support points of the shaft is at most 1/600 of the length of the torsion bar device, - the octagonal shaft piece is of multi-part design over the length, wherein it is provided with a shaft coupling, - this shaft coupling is formed from two or four sheet metal sections which are screwed to one another at the flange points, and - at least one of the pieces of each of these sheet metal sections that adjoins the drive shaft is screwed to the drive shaft in the region between the flanges.