1.1 These reference radiographs are reproductions of original radiographs and are supplied as a means of establishing the categories and severity levels of discontinuities in steel castings that may be revealed by radiographic examination. They may be used in accordance with contractual specifications.

1.2 Radiographs for evaluation are to be compared with these reference radiographs for classification on the basis of the category and severity level of the discontinuity. These reference radiographs are applicable to nominal section thicknesses of 4 1/2 to 12 in. (114 to 305 mm).

1.3 These reference radiographs consist of two set as follows:

1.3.1 2-MV X Rays and Cobalt-60 -This includes cobalt-60 or equivalent isotope radiation and from 2 MV up to 4 MV X rays.

1.3.2 4-MV to 30-MV X rays.

1.4 Each set is for comparison only with the radiographs produced with equivalent radiation and consists of three categories of graded discontinuities in increasing severity levels, and three categories of ungraded discontinuities furnished as examples only, as follows:

1.4.1 Category A -Gas porosity; severity levels 1 through 5.

1.4.2 Category B -Sand and slag inclusions; severity levels 1 through 5.

1.4.3 Category C -Shrinkage; 3 types:

1.4.3.1 Type 1 -Severity levels 1 through 5.

1.4.3.2 Type 2 -Severity levels 1 through 5.

1.4.3.3 Type 3 -Severity levels 1 through 5.

1.4.4 Category D -Crack; one illustration D5 in pre-1972 documents.

1.4.5 Category E -Hot tear; one illustration D3 in pre-1972 documents.

1.4.6 Category F -Insert; one illustration EB2 in pre-1972 documents.

1.5 The use of this document is not intended to be restricted to the specific energy level or to the absolute thickness limits that are contained in the document title. The title is intended to be descriptive and not restrictive. The document may be used, where there is no other applicable document, for other energy levels or thicknesses, or both, for which it is found to be applicable and for which agreement has been reached between purchaser and manufacturer.

Note 1-The two sets of reference radiographs consist of 56 radiographic reproductions (28 for each set) in 8 1/2 by 11-in. ring binders. In 1972, the number of categories was increased from five to six and the number of radiographic reproductions reduced from 37 to 28 for each set.

1.6 The values stated in inch-pound units are to be regarded as the standard.