A working cylinder, comprising a cylinder tube with a main longitudinal axis, a first closure part, a second closure part and a piston unit, wherein the cylinder tube comprises a first cylinder tube end and a second cylinder tube end, wherein the first closure part is arranged at the first cylinder tube end, wherein the second closure part is arranged at the second cylinder tube end, wherein the cylinder tube and the closure parts (3, 4) form a cylinder interior, wherein the piston unit is arranged in the cylinder interior such that it is axially displaceable along the main longitudinal axis and forms at least one working chamber in the cylinder interior, wherein the piston unit slidingly passes through the first closure part, wherein the first closure part is connected to the cylinder tube by means of a first circumferential laser ring weld seam and the second closure part is connected to the cylinder tube by means of a second circumferential laser ring weld seam in a positive-substance manner, wherein each of the laser ring weld seams (9, 10) forms a fluid-tight sealing plane, characterized in that at least one closure part (3, 4) comprises an axially opening, circumferential concave receiving contour in which the cylinder tube engages, wherein the receiving contour radially engages over the cylinder tube, and that a ring weld seam centre axis and the main longitudinal axis enclose a ring weld seam inclination angle (alpha) which is 110 to 160 degrees, and that a first circumferential sealing ring is arranged, axially spaced from the first laser ring weld seam, in the cylinder interior between the first closure part and a cylinder tube inner wall of the cylinder tube at its first cylinder tube end and forms a first pressure-separated ring section which is arranged between the first circumferential sealing ring and the first laser ring weld seam, and/or that a second circumferential sealing ring is arranged, axially spaced from the second laser ring weld seam, in the cylinder interior between the second closure part and a cylinder tube inner wall of the cylinder tube at its second cylinder tube end and forms a second pressure-separated ring section which is arranged between the second circumferential sealing ring and the second laser ring weld seam. comprising a cylinder tube with a main longitudinal axis, a first closure part, a second closure part and a piston unit, wherein the cylinder tube comprises a first cylinder tube end and a second cylinder tube end, wherein the first closure part is arranged at the first cylinder tube end, wherein the second closure part is arranged at the second cylinder tube end, wherein the cylinder tube and the closure parts (3, 4) form a cylinder interior, wherein the piston unit is arranged in the cylinder interior such that it is axially displaceable along the main longitudinal axis and forms at least one working chamber in the cylinder interior, wherein the piston unit slidingly passes through the first closure part, wherein the first closure part is connected to the cylinder tube by means of a first circumferential laser ring weld seam and the second closure part is connected to the cylinder tube by means of a second circumferential laser ring weld seam in a positive-substance manner, wherein each of the laser ring weld seams (9, 10) forms a fluid-tight sealing plane, characterized in that at least one closure part (3, 4) comprises an axially opening, circumferential concave receiving contour in which the cylinder tube engages, wherein the receiving contour radially engages over the cylinder tube, and that a ring weld seam centre axis and the main longitudinal axis enclose a ring weld seam inclination angle (alpha) which is 110 to 160 degrees, and that a first circumferential sealing ring is arranged, axially spaced from the first laser ring weld seam, in the cylinder interior between the first closure part and a cylinder tube inner wall of the cylinder tube at its first cylinder tube end and forms a first pressure-separated ring section which is arranged between the first circumferential sealing ring and the first laser ring weld seam, and/or that a second circumferential sealing ring is arranged, axially spaced from the second laser ring weld seam, in the cylinder interior between the second closure part and a cylinder tube inner wall of the cylinder tube at its second cylinder tube end and forms a second pressure-separated ring section which is arranged between the second circumferential sealing ring and the second laser ring weld seam.