These are folds of metal that have been rolled or pressed into the surface. They are treated similarly to cracks if they are open or have sharp roots.
The official standard is a copyrighted document. While snippets and summaries are available on platforms like Scribd for preview, the full, legal version for professional use must be purchased directly from the MSS Standards Store or authorized resellers like ANSI. Exploring MSS SP-55: Can You Spot Casting Irregularities? mss sp 55 pdf
According to the official , the standard covers: These are folds of metal that have been
The standard requires that pipe and fittings be subjected to various tests and inspections, including: mss sp 55 pdf