We have been using ASME materials. Mostly the ASME materials are designated as
"Specification no. - Grade - Class", like
SA-182 Gr. F11 Class 2

I was under the impression that the class signifies the heat treated condition of the material. But I noticed ASME SA-182 Gr. F22 Class 1 and Class 3 both comes in annealed or normalized and tempered condition. The chemical composition is also the same. But the mechanical properties are different.

But if you notice there will significant changes in mechanical properties (Tensile strength) between materials of similar grade and different class. So what is the basis behind the "class"?

Regards
Suri

hello,

the answer to your question is rather simple.
The class of material is designated to distinguish material with different properties within the scope of a material specification.
I hope you will feel better with this answer.

Horst Michael
ASME Delegate Germany