Does it mean " Pressure Containing castings and Structural Castings" or "Pressure Containing-Structural Castings"?
closed as not a real question by Kris, Matt Эллен, jwpat7, aedia λ, simchona♦ May 19 '12 at 0:21
It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center.If this question can be reworded to fit the rules in the help center, please edit the question.
Without more context it really can't be determined. But my best guess would be that it means the former:
Is this a section heading in a catalog?
The two terms are alternatives.
Pressure containing castings are designed to hold and confine higher pressures within.
Structural castings merely provide the strcture and cannot (be expected to) withstand high pressures.
The reference here is to the two different classes of products -- both of them.