ASTM E155 distinguishes between fine porosity (small, diffuse voids) and coarse porosity (large, irregular voids). A Level 3 fine porosity might still pass, while a Level 3 coarse porosity would likely fail pressure-retaining components.
Critical note: The levels are relative to a master set of radiographs. You do not guess. You place your production radiograph next to (or digitally overlay) the ASTM reference of the same thickness range and match the severity.
Porosity is the most common casting defect. It appears as a dark, round, or elongated indication on a radiograph. ASTM E155 defines five severity levels for each type of porosity. Level 1 is the smallest allowable limit, while Level 5 represents the most extensive (typically rejectable) condition. astm e155 porosity levels pdf repack
Without these reference levels, two inspectors could look at the same radiograph and disagree on "acceptable vs. rejectable." The ASTM E155 standard provides the universal ruler.
Yes, but only for rough sorting. For official acceptance, you need a calibrated NDT display (luminance > 300 cd/m², ambient light < 10 lux). Critical note: The levels are relative to a
If you are compiling or evaluating an ASTM E155 porosity levels PDF repack, ensure it contains these critical data tables:
| Feature | Standard PDF | Repacked PDF | |---------|--------------|--------------| | Searchable text | ❌ Often not | ✅ Yes (OCR applied) | | Bookmarked sections | ❌ Rarely | ✅ Porosity levels bookmarked | | High-contrast images | ❌ Scans degrade quality | ✅ Digitally enhanced radiographs | | Thickness correction table | ❌ Missing | ✅ Embedded as Appendix A | | Printer-friendly layout | ❌ 200 pages of fluff | ✅ Condensed to 15 essential pages | Porosity is the most common casting defect
A proper "repack" of the ASTM E155 porosity levels PDF should include:
Use a light box (brightness > 3000 cd/m²). Place your radiograph next to the printed reference from the PDF (printed at true scale). Move through Levels 1 to 5 until the density and distribution match.