ASME SA516/ASTM A516 – Gr.70

What’s the difference between ASTM A516 Gr. 70 and ASME SA516 Gr. 70? In fact, the mechanical and chemical properties of the steels are identical and it is the producer of the standard that is the key difference. ASTM, the American Society for Testing and Materials, produces standards that define limits and parameters on a product’s properties and the methods of testing those properties. ASME, the American Society of Mechanical Engineers, specifies materials to be used in the manufacture and construction of particular items. The relevance of this to pressure vessels is that ASME publishes design codes and standards for the manufacture of vessels and within these a particular material standard will be endorsed. ASME “acquires” ASTM specifications in this way and its pressure vessel code committee assigns an “S” to the relevant ASTM standard. So A516 becomes SA516 when ASME acquires it

Despite its wide use and application, A516 / SA516 is a remarkably straightforward standard in its basic form with just five key chemical elements specified along with three mechanical properties. It does not even need to be heat treated in any way.

In many cases the stringent requirements of engineers and designers require much greater controls than this. These are in part provided by a specification called ASTM A20 or ASME SA20 (Specification for General Requirements for Steel Plates for Pressure Vessels). This specification outlines the testing and retesting methods and procedures, permissible variations in dimensions and mass, quality and repair of defects, marking, loading, and ordering information. It also contains a list of supplementary requirements which can be added to the basic A516 / SA516 specification when additional control, testing, or examination is required to meet end use requirements.
The supplementary requirements in A20 / SA20, there are seventeen of them, are designated numbers (S1, S2, S3, and so on) and cover things like ultrasonic testing (S8, S11 or S12 depending on the type of ultrasonic test), charpy v-notch impact tests (S5), and product chemical analysis (S2).

As a matter of course, and in order to provide the best possible service to our customers, Brown McFarlane stocks ASTM A516 Gr. 70 and ASME SA516 Gr. 70 plates with numerous supplementary requirements included and all noted on the material test certificate supplied with each plate.