1.1 This specification2 covers austenitic steel castings for valves, flanges, fittings, and other pressure-containing parts (Note 1).
Note 1:Carbon steel castings for pressure-containing parts are covered by Specification A216/A216M, low-alloy steel castings by Specification A217/A217M, and duplex stainless steel castings by Specification A995/A995M.
1.2 A number of grades of austenitic steel castings are included in this specification. Since these grades possess varying degrees of suitability for service at high temperatures or in corrosive environments, it is the responsibility of the purchaser to determine which grade shall be furnished. Selection will depend on design and service conditions, mechanical properties, and high-temperature or corrosion-resistant characteristics, or both.
1.2.1 Because of thermal instability, Grades CE20N, CF3A, CF3MA, and CF8A are not recommended for service at temperatures above 800 °F [425 °C].
1.3 Supplementary requirements of an optional nature are provided for use at the option of the purchaser. The Supplementary requirements shall apply only when specified individually by the purchaser in the purchase order or contract.
1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
1.4.1 This specification is expressed in both inch-pound units and in SI units; however, unless the purchase order or contract specifies the applicable M-specification designation (SI units), the inch-pound units shall apply. Within the text, the SI units are shown in brackets or parentheses.
1.5This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
What ASTM A351 means for austenitic steel castings used in pressure parts
ASTM A351/A351M is the standard specification for austenitic steel castings used for pressure-containing parts. It is widely used for valves, flanges, fittings, pump casings, and other cast components used in pressure, corrosion, and high-temperature service environments.
It covers austenitic steel castings for valves, flanges, fittings, and other pressure-containing parts.
It defines requirements for chemical composition, heat treatment, mechanical properties, and casting quality.
It supports material selection for pressure equipment used in chemical, oil and gas, power, marine, and industrial applications.
Video credit: Stainless steel casting supplier video on YouTube.
How ASTM A351 fits into the casting and pressure equipment lifecycle
ASTM A351 is applied during material specification, casting procurement, foundry production, heat treatment, testing, inspection, and final acceptance. It helps ensure that cast pressure-containing parts meet required chemistry, mechanical performance, and service suitability expectations.
Material selection stage: choose the appropriate cast stainless steel grade for pressure, temperature, corrosion, and service conditions.
Foundry stage: produce castings using approved melting, casting, and heat treatment practices.
Testing stage: verify chemical composition, tensile properties, and other required quality checks.
Inspection stage: review dimensions, surface condition, defects, and documentation.
Service stage: use the casting in valves, fittings, flanges, pumps, and pressure-containing equipment.
Core building blocks of ASTM A351
Austenitic steel castings: corrosion-resistant cast stainless steel grades used in pressure applications.
Pressure-containing parts: components such as valves, flanges, fittings, and pump bodies that retain pressure.
Chemical composition: requirements for elements such as carbon, chromium, nickel, molybdenum, manganese, and silicon.
Heat treatment: required treatment followed by quenching or rapid cooling where specified.
Mechanical properties: tensile strength, yield strength, elongation, and related performance requirements.
Grade selection: choice of grades such as CF8, CF8M, CF3, CF3M, and other austenitic casting grades based on service needs.
What ASTM A351 evaluates in practice
Material chemistry: whether the casting meets the required alloy composition for the selected grade.
Mechanical performance: whether the casting meets required tensile and strength properties.
Heat treatment condition: whether the casting has received required treatment for service suitability.
Pressure part suitability: whether the casting is appropriate for valves, fittings, flanges, and similar components.
Corrosion resistance: whether the selected grade fits the intended corrosive environment.
Purchaser requirements: whether supplementary tests or additional inspection requirements are needed.
High-value use cases of ASTM A351
Stainless steel valve bodies and bonnets.
Flanges and fittings for pressure piping systems.
Pump casings and pressure-containing cast components.
Chemical processing equipment exposed to corrosive media.
Oil and gas, marine, power generation, and industrial pressure applications.
Integration with related casting and pressure material standards
ASTM A216/A216M: carbon steel castings for pressure-containing parts.
ASTM A217/A217M: martensitic stainless and alloy steel castings for pressure-containing parts.
ASTM A743/A743M: corrosion-resistant iron-chromium and iron-chromium-nickel castings for general application.
ASTM A995/A995M: austenitic-ferritic duplex stainless steel castings for pressure-containing parts.
ASME SA-351: ASME Boiler and Pressure Vessel Code material specification related to ASTM A351.
How to apply ASTM A351 in a real procurement program
Define the pressure part type, service fluid, temperature, pressure, corrosion exposure, and design code requirements.
Select the appropriate ASTM A351 grade based on corrosion resistance, temperature, weldability, and mechanical requirements.
Specify required heat treatment, testing, inspection, certification, and supplementary requirements.
Review foundry documentation, material test reports, chemical analysis, and mechanical test results.
Inspect casting quality, dimensions, markings, and traceability before acceptance.
Control substitutions carefully because grade changes can affect corrosion resistance and service life.
Common pitfalls and how to avoid them
Choosing the wrong grade: match CF8, CF8M, CF3, CF3M, or other grades to the actual service environment.
Ignoring corrosion exposure: consider chlorides, acids, temperature, and process chemistry before selecting material.
Weak material traceability: require complete material test reports and casting identification.
Missing supplementary requirements: specify extra testing or inspection when project conditions demand it.
Assuming wrought and cast grades are identical: understand the difference between cast designations and wrought stainless steel grades.
Case study: selecting ASTM A351 CF8M for a chemical valve application
A chemical plant needed stainless steel valve bodies for a chloride-containing process line. The procurement team compared common ASTM A351 casting grades and selected CF8M because the molybdenum-bearing grade provided better suitability for chloride exposure than standard CF8.
The team included ASTM A351 grade requirements in the purchase specification.
The supplier provided chemical and mechanical test documentation for the castings.
The plant reduced material mismatch risk and improved pressure equipment reliability.
Frequently Asked Questions
1. What is ASTM A351?
ASTM A351/A351M is the standard specification for austenitic steel castings used for pressure-containing parts.
2. Where is ASTM A351 used?
It is used for cast valves, flanges, fittings, pump casings, and other pressure-containing components.
3. What are common ASTM A351 grades?
Common grades include CF8, CF8M, CF3, and CF3M, depending on corrosion resistance, carbon level, and service needs.
4. Is ASTM A351 used for stainless steel castings?
Yes. ASTM A351 is commonly used for austenitic stainless steel castings for pressure-containing service.
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