A work kit, comprising a work interface accessory and a friction stir welding head, wherein the work interface accessory is intended to be assembled on the friction stir welding head and is able to be disassembled relative to the friction stir welding head, wherein the work interface accessory comprises an external body having a first side wall delimiting a first recess open on top for introduction of a rotating portion (301, 302) of the friction stir welding head and for withdrawal of the friction stir welding head, the work interface accessory comprises an upper plate, which is fastened on an upper portion of the first side wall or which is integral with the upper portion of the first side wall, which has a first upper opening connected to the first recess and which comprises fastening portions, allowing removable fastening against the friction stir welding head, the work interface accessory comprising a central shaft, which is rotatably assembled in the first side wall around an axis of rotation, the central shaft having a second lower portion, which projects from a first lower portion of the first side wall downwards and which is intended to carry a work tool, the central shaft comprising in the first recess an internally toothed coupling sleeve to allow the central shaft to be driven in rotation, when an externally toothed ring gear of the rotating portion (301, 302) of the head is introduced into the sleeve and rotates in the internally toothed coupling sleeve around the axis of rotation, wherein the friction stir welding head comprises a frame and the lower rotating portion (301, 302), rotatably assembled relative to the frame and protruding therefrom downwards, with the rotating portion (301, 302) of the head comprising the externally toothed ring gear to allow the internally toothed coupling sleeve to be driven in rotation, the frame comprising a second plate for bearing against the upper plate, the second plate comprising a gripping mechanism comprising a system of clamps, which is facing downwards and which is intended to be fastened on the fastening portions (131, 13) of the upper plate of the accessory, wherein the clamps are actuatable by a pressurized fluid to be either in a position of gripping the fastening portions, or in a position of releasing the fastening portions, wherein the head comprises a source that can be controlled to supply or not to supply pressurized fluid to the clamps, wherein the clamps are configured such that the supply of the pressurized fluid to the clamps causes them to move from the position of gripping of the fastening portions to the position of releasing of the fastening portions and such that the absence of supply of the pressurized fluid to the clamps allows them to move from the position of releasing of the fastening portions to the position of gripping of the fastening portions. wherein the work interface accessory is intended to be assembled on the friction stir welding head and is able to be disassembled relative to the friction stir welding head, wherein the work interface accessory comprises an external body having a first side wall delimiting a first recess open on top for introduction of a rotating portion (301, 302) of the friction stir welding head and for withdrawal of the friction stir welding head, the work interface accessory comprises an upper plate, which is fastened on an upper portion of the first side wall or which is integral with the upper portion of the first side wall, which has a first upper opening connected to the first recess and which comprises fastening portions, allowing removable fastening against the friction stir welding head, the work interface accessory comprising a central shaft, which is rotatably assembled in the first side wall around an axis of rotation, the central shaft having a second lower portion, which projects from a first lower portion of the first side wall downwards and which is intended to carry a work tool, the central shaft comprising in the first recess an internally toothed coupling sleeve to allow the central shaft to be driven in rotation, when an externally toothed ring gear of the rotating portion (301, 302) of the head is introduced into the sleeve and rotates in the internally toothed coupling sleeve around the axis of rotation, wherein the friction stir welding head comprises a frame and the lower rotating portion (301, 302), rotatably assembled relative to the frame and protruding therefrom downwards, with the rotating portion (301, 302) of the head comprising the externally toothed ring gear to allow the internally toothed coupling sleeve to be driven in rotation, the frame comprising a second plate for bearing against the upper plate, the second plate comprising a gripping mechanism comprising a system of clamps, which is facing downwards and which is intended to be fastened on the fastening portions (131, 13) of the upper plate of the accessory, wherein the clamps are actuatable by a pressurized fluid to be either in a position of gripping the fastening portions, or in a position of releasing the fastening portions, wherein the head comprises a source that can be controlled to supply or not to supply pressurized fluid to the clamps, wherein the clamps are configured such that the supply of the pressurized fluid to the clamps causes them to move from the position of gripping of the fastening portions to the position of releasing of the fastening portions and such that the absence of supply of the pressurized fluid to the clamps allows them to move from the position of releasing of the fastening portions to the position of gripping of the fastening portions.