An assembly tool for assembly of a first component of a prosthesis to a second component of the prosthesis for use in joint arthroplasty. The tool includes a first member which can engage the first component and a second member which can engage the second component. The second member includes a cap having a threaded recess and further includes a threaded rod adapted to engage the threaded recess so as to move the second member relative to the first member and the threaded rod is made of a harder metal than the threaded recess.
