Abstract: A tool for the manufacture of the outer member of a cross groove type constant velocity ratio universal joint has two sets of first and second elements disposed circumferentially between one another about the axis of the tool with the elements having portions which interfit to define a surface whose shape corresponds to that required in the joint, the portions having formations which form the sets of grooves, and with the elements so shaped that portions of the first elements can be moved radially inwardly to disengage their formations from the grooves.

Abstract: A tool for use in manufacture of a hollow article with an undercut internal surface, such as the outer member of a constant velocity ratio universal joint, comprising first and second elements (34,38) together defining the shape required in the article interior and an internal cavity (40). An expander (23) fits in the cavity to hold the elements in their operative positions, and the first elements have parallel or outwardly convergent sides which enable their inward movement between the second elements after withdrawal of the expander from the cavity. After such inward movement, the first elements can be withdrawn from the shaped article, followed by the second elements.