For digital radiography applications, separate standards apply:
: Standard computer monitors cannot replicate the precise optical density required to grade actual X-rays accurately.
is a set of radiographic plates used to evaluate internal discontinuities in castings. These reference radiographs allow inspectors to compare a casting’s X-ray image against known severity levels of defects, including: Gas porosity: Smooth-edged, spherical cavities. astm e155 porosity levels pdf repack
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.
A persistent pain point in the foundry industry is engineering prints that vaguely state "Free of Porosity per ASTM E155". Without citing a specific severity level (e.g., Grade A vs. Grade B), this leaves too much room for subjective interpretation and can result in scrapped parts or delayed PPAP approvals. Utilizing Industry Resources for Compliance No matter how good the scan, a PDF
: The inspector determines whether the observed severity level falls within the limits specified by the engineering requirements.
Understanding ASTM E155 porosity levels is essential for anyone involved in the production, inspection, or quality assurance of aluminum and magnesium castings. By classifying porosity from levels 1 through 8, the standard ensures that components meet necessary structural integrity standards. While searching for an "ASTM E155 porosity levels PDF" can provide quick reference, always ensure that final inspections are conducted using official, authorized ASTM E155 reference radiographs. You cannot see the mottle effect in the
. Higher severity grade numbers indicate MORE severe discontinuities. Level 8 represents the most porosity, not the least.
To ensure your facility remains compliant during audits (such as AS9100 or NADCAP certifications), observe the following practices when working with ASTM E155 porosity levels:
Distinct from porosity, gas holes refer to individual gas entrapments that may be more isolated or larger in size.
commonly used by specific industries (e.g., aerospace) for these levels?