Abstract: A parts fastener has a body having at one of its ends a flanged head projecting from the body. For that purpose the body evinces a central cavity communicating with the outside and includes at least a wall portion of which the inner side bounds part of the cavity, and which elastically deforms under an external force applied to the wall portion. The wall portion has, on its outer side, a projection which together with the head flange bounds a jaw by means of which the fastener may be inserted into the part to which it must be affixed. The projection opens on account of the deformation of the wall portion and frees the part and the fastener from each other. The device may also include means to cause the deforming force from the outside.