This part of ISO 9448 specifies the main dimensions and tolerances, in millimetres, of guide bushes of form D, headed ball cage bushes, type 1, intended for use in press tools and to be mounted in the clamp plate with transition fit and fixed to the plate by means of screws.It gives guidance on the materials, and specifies the hardness and the designation of bushes in accordance with this part of ISO 9448.