ASTM E155 categorizes internal discontinuities into distinct types. Porosity, which is caused by trapped gas or material shrinkage during cooling, is graded by severity levels ranging from to Level 8 (most severe) . 1. Gas Porosity
Areas subjected to high cyclic stress, pressure containment, or structural loading. These demand tight tolerances (Level 1 or Level 2).
No matter how good the scan, a PDF is NOT a radiographic film. The original E155 plates have a film density of 2.0 to 4.0. On a standard 1080p monitor, you lose some of the subtle grain structure. You cannot see the mottle effect in the background of the radiograph as clearly as you can on a lightbox. For critical aerospace work (NADCAP audits), you still need the physical plates. The auditor will fail you if you only have the PDF.
Smooth-edged dark spots, round or elongated; can occur individually or in clusters.
When looking for , users are often searching for a "repack," "reissue," or a digital PDF version of the reference radiographs. Why search for a repack?
: The casting is exposed to X-ray or gamma radiation to produce a radiograph.
In the world of nondestructive testing (NDT) and quality assurance for metal castings, ASTM E155 stands as one of the most essential standards ever developed. For inspectors, quality engineers, and manufacturing professionals working with aluminum and magnesium castings, understanding ASTM E155 porosity levels is not just a matter of compliance—it is fundamental to ensuring product integrity and safety.
The standard provides reference radiographs used to evaluate the severity of discontinuities in aluminum and magnesium castings . It is a critical tool for radiographic testing (RT), allowing inspectors to compare actual X-ray films against standardized "plates" to determine if a part meets specific quality requirements. ASTM E155 Porosity and Discontinuity Levels
For inspectors, engineers, and quality personnel, having quick access to via a PDF or interpreted repack guide is essential for determining whether a part meets acceptance criteria.
: Meeting military-grade inspection criteria for cast hardware. Types of Discontinuities in ASTM E155