The invention relates to a camshaft, in particular for motor vehicle engines, comprising an outer shaft (1), an inner shaft (2) arranged coaxially in the outer shaft (1), first functional elements (3) rigidly arranged on the outer shaft (1), second functional elements (4a, 4b), which are rotatably arranged on the outer shaft (1) and fastened to the inner shaft (2) in a rotationally fixed manner, and a phase adjuster (5) connected to the outer shaft (1) and the inner shaft (2) for rotating the inner shaft (2) relative to the outer shaft (1), wherein the phase adjuster (5) is fastened to the inner shaft (2) and thereby a torque is applied. According to the invention, one of the functional elements (4a, 4b) connected to the inner shaft (2) in a rotationally fixed manner has tool accommodation surfaces (11) on the cylindrical surface side outside of a functional surface (12a, 12b). The invention further relates to such a functional element.