These reference radiographs illustrate various types and degrees of discontinuities occurring in thin-wall steel investment castings. (The reference radiographs are considered to be applicable to all thin-wall steel castings, requiring close tolerances. Such castings generally include those made by the lost wax, frozen mercury, ceramicast or shell mold processes.)

They are intended to provide:

• A guide enabling recognition of thin-wall steel casting discontinuities and their differentiation both as to type and degree through radiographic examination.

• Example radiographic illustrations of discontinuities and a nomenclature for reference in acceptance standards, specifications, and drawings.

The set of reference radiographs, produced with X Rays in the range from 130 to 250 kVp, consist of 16 plates 8-1/2 by 11 in. ( 216 by 279 mm) in a 9-3/4 by 11-1/2 in. ( 248 by 292-mm) ring binder.