1.2.3 Unless otherwise specified in a purchaser supplier agreement (see 1.1), each volume is for comparison only with production radiographs produced with radiation energy levels within the thickness range covered by this standard. Each volume consists of three categories of graded discontinuities in increasing severity levels, and three categories of ungraded discontinuities. Reference radiographs containing ungraded discontinuities are provided as a guide for recognition of a specific casting discontinuity type where severity levels are not needed. Following is a list of discontinuity categories, types and severity levels for the adjunct reference radiographs of this standard:
1.2.3.1 Category A—Gas porosity; severity levels 1 through 5.
1.2.3.2 Category B—Sand and slag inclusions; severity levels 1 through 5.
1.2.3.3 Category C—Shrinkage; three types:
(1) Ca Linear Shrinkage—Severity levels 1 through 5 (called Type 1 in previous revisions).
(2) Cb Feathery Shrinkage —Severity levels 1 through 5 (called Type 2 in previous revisions).
(3) Cc Sponge Shrinkage—Severity levels 1 through 5 (called Type 3 in previous revisions).
1.2.3.4 Category D—Crack; one illustration D5 in pre-1972 documents.
1.2.3.5 Category E—Hot tear; one illustration D3 in pre-1972 documents.
1.2.3.6 Category F—Insert; one illustration EB2 in pre-1972 documents.