I don't have a copy of the standard, but I think you better double check your number. The specification you reference is: A270-01 Standard Specification for Seamless and Welded Austenitic Stainless Steel Sanitary Tubing .
For everyone's education, the specification referred to in butelja's post is from ASTM International. It appears that either the original post has an incorrect ASTM specification number, or the original number refers to a non-ASTM specification.
Ahh, yes, it is ISO 3506. A2 Property Class 70 is an austenitic stainless steel essentially similar to alloy 304, although it has higher mechanical property requirements - yield strength minimum = 450 MPa, and ultimate tensile strength minimum = 700 MPa. The specification is availble at