A tube assembly for an endoscope includes a steering device and a flexible tube device on a proximal side. The tube assembly includes an inner sleeve. An outer sleeve receives one end portion of the inner sleeve in an axial direction, for connection of the flexible tube device to the steering device. A flow opening is formed in a portion of the outer sleeve disposed around the inner sleeve. A distribution groove is formed between an outer wall surface of the inner sleeve and an inner wall surface of the outer sleeve, to extend from the flow opening. A seal cavity is formed in the inner and outer sleeves to extend from the distribution groove in a direction away from the flow opening. Flowing solder material is supplied in the flow opening, charged in the distribution groove and the seal cavity, for attaching the outer sleeve to the inner sleeve.
