Abstract: A method of mechanically locking an interior element in an outer body with deformable material. The deformable material is permanently deformed against the interior element through circumferentially spaced radial holes in the outer body. This forms a core of deformed material between the inner element and outer body, with some deformable material in each opening. The radial position of the inner element can then be adjusted without shifting the inner element axially, using punch or press elements which are inserted in selected radial openings to further deform the material and thus adjust the inner element radially. The method is particularly useful for centering an optical fiber fixed within an inner element, by so adjusting the radial position of the inner element in an outer ferrule body.