– Non-metallic materials (like sand or slag) trapped in the casting. Type IV: Gas Porosity – Small voids or bubbles caused by trapped gas. Type V: Chaplets
The standard provides a uniform, visual method for identifying and evaluating surface irregularities in steel and iron castings. It is primarily intended to supplement ASTM specifications (such as ASTM A216, A217, and A351) by defining what is "acceptable" versus "rejectable" through a set of . Visual Evaluation System mss sp-55 standard pdf
: If the irregularity is more severe than the reference photo, the casting must be repaired (usually via welding) or scrapped. – Non-metallic materials (like sand or slag) trapped