ASTM A27 Standard Specification for Steel Castings, Carbon, for General Application

Get Certified ASTM A27 Testing for Reliable Carbon Steel Casting Quality 

Certification confirms that carbon steel castings meet the corresponding ASTM A27 requirements, such as chemical composition and mechanical properties. ASTM A27 certified testing determines the casting’s conformity before manufacturers accept it for general industrial applications. Testing and certification ensure conformance to ASTM A27 requirements and reduce the risk of material failures when releasing products to the market. 

The scope of ASTM A27 covers: 

• Material type: Carbon steel castings for general use. 
• Purpose: Establishes requirements for castings that require up to 70 ksi (485 MPa) minimum tensile strength.
• Properties measured: Chemical composition and (for applicable grades) tensile strength, yield strength, elongation, and reduction of area. 
• Method: Chemical analysis and mechanical testing to the requirements for the designated grade and class. 
• Result: Laboratory reports of chemical and applicable mechanical test results are reported for comparison to the specified requirements. 
• Test Limitations: The requirements for a test vary from class to class and grade to grade, so the testing requirements for the indicated grade and class shall be applied in the laboratory. 
• Use conditions: The specification is for general applications and contains grades which may be joined by fusion welding to other wrought steel or steel castings. 
• Applications: The specification is used for carbon steel castings for general engineering and industrial applications. 

What are the Uses of ASTM A27 Specification?

ASTM A27 is used for quality control and material verification for carbon steel castings for general applications. Manufacturers, purchasers, and laboratories use the specification to evaluate chemical composition and applicable mechanical properties. This standard-

• Assists manufacturers in confirming the desired grade of carbon steel casting.
• Assists with chemical composition testing for production and acceptance.
• Helps laboratories evaluate tensile strength and other required mechanical properties.
• Helps to verify heat-treated grades against specified requirements.
• Supports buyers in evaluating and comparing castings to material standards.
• Supplies certified test data for quality control and material acceptance.

What Materials Can Be Tested Under ASTM A27? 

ASTM A27 is applicable to carbon steel castings that have a maximum specified tensile strength of 70 ksi (485 MPa) or less and are intended for general applications. Requirements vary according to grade; some grades require chemical analysis only, others require heat treatment or mechanical testing or both. The specification includes seven grades: Grade N-1, Grade N-2, Grade U-60-30, Grade 60-30, Grade 65-35, Grade 70-36, and Grade 70-40.

Why is ASTM A27 Important? 

ASTM A27 is significant because it offers a standard specification for the making and quality assurance of carbon steel castings for general applications. The specification ensures that castings produced under the standard undergo comprehensive testing to confirm reliability under different operating conditions. ASTM A27 specifies both chemical composition and mechanical properties, as well as heat treatment requirements, which help ensure uniformity, particularly in applications that call upon the product for strength and weldability. The specification also contains supplementary requirements for use, where further testing or restrictions are needed as a result of the purchaser’s requirements. 

ASTM A27 Testing Process and Data Collection

Testing begins with taking representative samples of carbon steel castings or separately cast test bars and determining the appropriate grade and class. The technician then conducts heat and product analysis to determine the chemical composition of carbon, manganese, silicon, sulfur, and phosphorus. They heat treat castings for applicable grades to full annealing, normalizing, normalizing and tempering, or quenching and tempering after the cooling process. Tensile testing is done to measure tensile strength, yield point, elongation, and reduction of area for Grades U-60-30, 60-30, 65-35, 70-36, and 70-40. They compare test results with the mechanical requirements specified for the appropriate grade. Lastly, the analyst documents all testing conditions and records any differences from the standard testing process. 

Common Challenges and Troubleshooting

The common challenges involve the selection of the proper grade and class, preparation of a representative mechanical specimen, and use of the correct testing requirements. The problem becomes exacerbated with variations in casting quality, and the standard requires that heat treatment be performed after castings have fully cooled.   Laboratories minimize the risk of error by keeping records of specimen identification, confirming the required grade before testing, inspecting equipment condition, and reviewing chemical and mechanical requirements before reporting.

• The laboratory provides tensile strength, yield point, elongation, and reduction of area figures for the appropriate grade.
• The technician determines the casting test grade and class.
• The analyst measures the properties at the specified test conditions and correlates them with the casting and heat treatment conditions being tested.
• When interpreting test results, the engineer considers the heat treatment condition, casting quality, and dimensional tolerances.
• Engineers rely on these measured properties to help them meet the material specification and ensure it is suitable for use in general applications. 

Link to ASTM A27