Corrugated tube made of plastic, particularly for sheathing electrical wires, having wave crests and wave troughs, which follow alternately after one another and which are distributed over its length, wherein the wave crests comprise a radial height (h) with respect to the wave troughs, and having a slit running along a surface line, wherein the border areas (5, 6) of the corrugated tube, which are located on both sides of the slit, comprise shape formations (7, 8, 9) at the wave crests, by which, when the border areas (5,6) overlap, a detachable fastening can be formed, and wherein every shape formation further includes, when viewed in a circumferential direction of each wave crest, three shape formations (7, 8, 9) which follow each other directly, each having a different width (B1, B2, B3) that is either decreasing or increasing with the sequence at the wave crest, wherein the slit cuts all shape formations having an intermediate width into two parts (8A, 8B), each of which is associated with one border area (5, 6), all shape formations (7, 8, 8A, 8B, 9) - when viewing the radial cross section of the wave crests - are further arranged to each other identical in position and shape, and the shape formations (7, 8) having the largest width and the middle width are provided with a radial recess (11, 12) being opened towards the inside on their radial bottom sides, which recess comprises at the shape formation having the largest width a size, in which the outer shape of the shape formation having the middle width is radially insertable, and which recess has at the shape formation having the middle width a size, in which the outer shape of the shape formation having the smallest width is radially insertable, characterized in that the lateral surface of the corrugated tube, in its unclosed state, is respectively formed in its wave troughs and wave crest by two arcs (S1, S2; s1, s2) having different radii (R1, R2; r1, r2), wherein the arcs (S1; s1) having the larger radius and the arcs (s2; s2) having the smaller radius are arranged at the same angular positions in the cross section of the corrugated tube and the larger radius (R1;r1) is larger than the respective smaller radius (R2;r2) by the wall thickness at the wave trough, each of the arcs (S2; s2) formed by the smaller radii leads at its end tangentially into the arc (S1; s1) formed by the respective larger radius (R1; r1) and is at its other end coupled via a substantially radial link (10, 10') with the other end of the respective arc (S1; s1) formed by the larger radius (R1; r1), wherein both radial links (10, 10') as well as the tangential junctions of the arcs (S1, s1) having the larger radii with the arcs (S2;s2) having the smaller radii are each arranged with the same angular positions to each other, and that all shape formations (7, 8, 9) are disposed in a portion of the arc (S2; s2) formed by the smaller radius (R2; r2), which is adjacent to the radial links (10, 10'), wherein it further applies: r1 = R1 - h and r2 = R2 - h, whereby h denotes the radial height of the wave crests, R1 the larger and R2 the smaller radius at the wave crest, and r1 the larger and r2 the smaller radius at the wave trough.