The invention relates to a machining tool with a detachable head comprising: a head (2) carrying at least one cutting blade (3), a slender body (4) and means (5) for detachably fastening the head to the slender body. It is characterized in that: the head (2) comprises, in the rear part, a rotating cylinder (6) centered on the axis of rotation of the tool, and in its so-called front end, at least one lug (8) projecting from the cylindrical surface, the slender body (4) has, opening into its side facing the head, a boring (9) for housing the aforementioned rotating cylinder and a hook (10) mounted on a pivot pin (11), which hook is movable, by a control means (12), between a so-called locked position in which said hook is engaged with the so-called pivot pin of the head and a so-called released position that makes it possible to insert and remove the cylinder from the boring, and in the cylindrical wall delimiting the boring (9), at least one notch (13) for receiving the aforementioned lug (8).