– Linear ruptures caused by internal stresses during cooling. These are generally unacceptable and require excavation and repair.
Establishing acceptable vs. unacceptable surface irregularities.
: The standard is intended for use on any 4 in. x 5 in. (100mm x 125mm) area of a casting surface.
: Linear fractures caused by internal stresses during cooling. These are generally unacceptable. mss sp-55 standard pdf
Valves, flanges, fittings, and other piping components.
In simple terms, it provides a standardized, visual method for evaluating surface discontinuities (commonly called "imperfections") in steel castings. These include defects like cracks, cold shuts, shrinkage, blowholes, and sand inclusions.
Do you need assistance mapping MSS SP-55 to ? Share public link – Linear ruptures caused by internal stresses during
– Grooves or rough textures left by post-casting finishing work.
Visual inspection (often complemented by comparison with reference photographs).
According to MSS Board Member David Woollums, the technical committee responsible for SP-55 recognized that the iron casting industry lacked a similar harmonized standard for surface defects. Discussions with casting experts and iron foundries confirmed that the visual method outlined in SP-55 could be effectively applied to iron castings, ensuring common acceptable criteria between foundries and customers. unacceptable surface irregularities
On , the Manufacturers Standardization Society announced the publication of the revised ANSI/MSS SP-55-2025 edition, which had been approved by the American National Standards Institute (ANSI) as a revised American National Standard (ANS). This revision represents the most significant update to the standard in years.
Originally adopted in 1961, MSS SP-55 was created to eliminate ambiguity in visual inspections. It is designed to supplement various ASTM specifications