What is the difference between A193 Grade B7 and SA193 Grade B7?

A193 is an ASTM (American Society for Testing and Materials) specification, whereas SA193 is from ASME (American Society of Mechanical Engineers). ASME repurposed the ASTM specification and added an “S”. The primary difference is the application.  While both specifications are designed for high temperature / high pressure service, SA193 may also be used in nuclear or other highly critical applications. When used in these critical applications, there may be some additional or supplemental requirements, however in most cases the ASTM and ASME specifications are generally the same.

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    @Li- The marking requirement for SA193 B7 bolts is “B7” and the requirement for SA194 2H nuts is “2H”. Both also require a manufacturer’s ID stamp.

    If I order SA193 B7, 3/8″ Dia x full threads, 1-12/” long (or 1-5/8″ LG), Qty 500 EA, how long will be taken to supply.

    @Behrouz- Any grade substitutions would need to be approved by the project engineer. What we can tell you is that A193 B7 and A307 are very different materials and are not considered interchangeable. A193 B7 is a high strength heat treated alloy, whereas A307 is low strength, mild steel.

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