A torsional damper (1) comprises a hub (2) coupled to a radial annular web (6); two guide washers; elastic members (9); and friction means, relative angular deflections of the guide washers and the annular web (6) being limited in a first rotation direction (D) by a first series of stops (23) of the guide washers that interact with a first series of protruding parts (25) of the annular web (6), and in a second rotation direction (R) by a second series of stops (24) of the guide washers that interact with a second series of protruding parts (26) of the annular web (6).