Abstract: A first part formed of hard metal to be joined to a second part of soft or malleable metal has an end portion of reduced diameter which is machined in the junction zone between the normal portion and the end portion of the first part in such a manner that the junction profile is a surface of revolution about the axis of the assembly and forms a groove. The junction surface is defined by a first portion of conical surface having a vertex directed towards the first part and by a second portion of conical surface directed towards the first part, the junction between the two portions of conical surface being formed by a beaded edge. The two parts are placed in a press in order to insert the edge of the second part into the groove of the second part.