1.1 ,These reference radiographs illustrate the types and degrees of discontinuities that may be found in aluminum-alloy and magnesium-alloy castings. The castings illustrated are in thicknesses of ¹/₄ ,in. (6.35 mm) and ³/₄ ,in. (19.1 mm). The reference radiograph films are an adjunct to this document and shall be purchased separately from ASTM International if needed.