Mss Sp-55 Standard Pdf Page
Surface variations that fall within the designated photographic guide limits for "Acceptable" do not require further conditioning or repair.
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.
MSS SP-55 characterizes twelve general types of surface irregularities that can appear on castings. Understanding these categories is essential for anyone performing visual inspections. The following table summarizes each type based on the standard's terminology:
To effectively implement MSS SP-55 in a production or quality control environment, consider the following best practices: mss sp-55 standard pdf
Legally, individual users may print one copy for internal use. However, MSS copyright prohibits resale or mass distribution. If you print it, ensure it is watermarked "CONTROLLED COPY."
– Shallow depressions from mold surface faulting.
is a widely accepted technical standard, first adopted in 1961. It is designed to act as a benchmark for visual inspection of iron and steel castings. MSS SP-55 characterizes twelve general types of surface
Severe cracks, deep tears, or massive inclusions that weaken the pressure boundary. Unacceptable components must be rejected or undergo approved weld remediation. MSS SP-55 vs. Other Casting Standards
MSS standards are protected by copyright laws. Authorized PDF copies must be purchased directly from the Manufacturers Standardization Society or licensed distributors (such as Techstreet, IHS Markit, or ANSI). Utilizing unauthorized, pirated, or outdated scanned PDFs can result in legal compliance liabilities and product failures due to using obsolete evaluation metrics. Summary Table: MSS SP-55 Visual Evaluation Workflow Description Surface Prep
– Grooves or gashes left behind during the removal of risers, gates, or flash. However, MSS copyright prohibits resale or mass distribution
: You can buy the official hard copy or PDF from the MSS Store or authorized distributors like the ANSI Webstore .
The set of 60 reference photographs is the heart of MSS SP-55. Each photograph has been carefully selected to represent a specific severity level of a particular defect type. When performing an inspection, the inspector visually compares the casting surface to the relevant reference photograph. If the irregularity is less severe than the first unacceptable example, the casting is generally considered acceptable.
Serves as a mandatory reference for ASME B16.34 pressure rating standards. Key Surface Irregularities Covered
Additionally, MSS SP-55 is frequently referenced in API standards, ASTM specifications, and ASME codes. For example, API's new casting quality standards explicitly require that all surfaces of a qualification casting be visually inspected in accordance with MSS SP-55, with reference photographs used to determine acceptability.
Note: The standard was updated to include iron and ductile iron castings in the 2025 edition. Key Features of the MSS SP-55 Standard