ASTM and SA 351 CF8M

'SA' is the prefix for ASME recognized ASTM materials (A-XXX); it allows for cross-referencing and "less confusion". For the most part they are identical/similar (plus ASME assigns allowable stress values at temperature) but some differences may exist, and some ASTM 'A-XXX' materials are not adopted according to the ASME codes.

For ASME work the SA-XXX must be used and ensured it is allowed according to the applicable ASME code section.

For a good history of how/why this came about see the Preface to ASME Section 2 Part A.

But just in case you don't have access to the codes (which I would hope you do) I have uploaded the SA-351 spec here (it should fall under "fair use" as there are MANY of them ):

http://ifile.it/pjtc58l