A milling tool holder, comprising: - a first holder part having a first cutting insert receptacle for receiving a first cutting insert and having a second cutting insert receptacle for receiving a second cutting insert; - a second holder part which is variably positionable with respect to the first holder part along a longitudinal axis in order to adjust a milling width, wherein the second holder part comprises a third cutting insert receptacle for receiving a third cutting insert and a fourth cutting insert receptacle for receiving a fourth cutting insert; - a locking mechanism for fixing the first and second holder parts (16, 18) to the adjusted milling width, wherein the first and the second holder parts (16, 18) are positioned with respect to one another in the mounted state in such a manner that the third cutting insert receptacle is arranged in the circumferential direction between the first cutting insert receptacle and the second cutting insert receptacle, and in that the second cutting insert receptacle is arranged in the circumferential direction between the third cutting insert receptacle and the fourth cutting insert receptacle, wherein the milling tool holder further comprises a spacer element which serves for adjusting the milling width and is arranged between the first and the second holder parts (16, 18), characterized in that the first holder part comprises a first cylinder surface for centering the spacer element, wherein the first cylinder surface extends symmetrically to the longitudinal axis, and that the second holder part comprises a second cylinder surface for centering the spacer element, wherein the second cylinder surface extends symmetrically to the longitudinal axis. - a first holder part having a first cutting insert receptacle for receiving a first cutting insert and having a second cutting insert receptacle for receiving a second cutting insert; - a second holder part which is variably positionable with respect to the first holder part along a longitudinal axis in order to adjust a milling width, wherein the second holder part comprises a third cutting insert receptacle for receiving a third cutting insert and a fourth cutting insert receptacle for receiving a fourth cutting insert; - a locking mechanism for fixing the first and second holder parts (16, 18) to the adjusted milling width, wherein the first and the second holder parts (16, 18) are positioned with respect to one another in the mounted state in such a manner that the third cutting insert receptacle is arranged in the circumferential direction between the first cutting insert receptacle and the second cutting insert receptacle, and in that the second cutting insert receptacle is arranged in the circumferential direction between the third cutting insert receptacle and the fourth cutting insert receptacle, wherein the milling tool holder further comprises a spacer element which serves for adjusting the milling width and is arranged between the first and the second holder parts (16, 18), characterized in that the first holder part comprises a first cylinder surface for centering the spacer element, wherein the first cylinder surface extends symmetrically to the longitudinal axis, and that the second holder part comprises a second cylinder surface for centering the spacer element, wherein the second cylinder surface extends symmetrically to the longitudinal axis. wherein the first and the second holder parts (16, 18) are positioned with respect to one another in the mounted state in such a manner that the third cutting insert receptacle is arranged in the circumferential direction between the first cutting insert receptacle and the second cutting insert receptacle, and in that the second cutting insert receptacle is arranged in the circumferential direction between the third cutting insert receptacle and the fourth cutting insert receptacle, wherein the milling tool holder further comprises a spacer element which serves for adjusting the milling width and is arranged between the first and the second holder parts (16, 18), characterized in that the first holder part comprises a first cylinder surface for centering the spacer element, wherein the first cylinder surface extends symmetrically to the longitudinal axis, and that the second holder part comprises a second cylinder surface for centering the spacer element, wherein the second cylinder surface extends symmetrically to the longitudinal axis.