provides a standard set of reference photographs used to classify and evaluate surface discontinuities in ferrous castings found during dry powder magnetic particle inspection. While you may find "free" PDF versions on file-sharing sites, these are generally unauthorised copies; the official, high-quality visual standards must be purchased directly from ASTM International or authorized distributors. ASTM International Overview of ASTM E125
Here is the catch with downloading a text-only PDF of this standard. astm e125 reference photographs pdf free download
I can help describe what those different ASTM categories look like if you're stuck! provides a standard set of reference photographs used