I found this thread searching about Pex A and Pex B, and wanted to add what I am seeing.
In addition to the image in the first post of this thread saying "All Sioux Chief PowerPEX tubing can be properly used with crimp, cinch, expansion & quick connect fittings", when you walk over to the fitting aisle at Menards they have some signs hanging by the expansion fittings telling you not to use them with blue or red PEX. So, this adds to the confusion.
It would be nice if the PEX had its manufacturing method or type printed on it with the other dozens of marks, but I don't think it's on there anywhere.
However, if you look at the Sioux Chief online catalog, they only list PEX-A as sold in coils or 20 ft sticks and only white (sticks) or natural (coils) in color. The PEX-B is listed as available in white, blue, or red.
So, I think what is happening is that the 5' and 10' red and blue Sioux Chief sticks, and also the red and blue coils of any length being sold at Menards are PEX-B. But they have the F1960 designation printed on them, indicating they are certified for expansion even though they are PEX-B. This might be a more recent certification.
Their catalog also mentions "All expansion joints made using PowerPEX Type-B tubing must be made with a self-rotating, power expansion tool to eliminate weak spots and avoid improper expansion rates."
So, I guess if you have a manual Pex A expansion tool that you want to use for a one-time repair, or you are a homeowner trying to save money with a cheaper tool, you need to buy a power tool to avoid leaks.
I am by no means a professional, but personally would avoid using the PEX-B with expansion fittings, as indicated on the yellow warning signs by the expansion fittings (although I think those are old signs that probably are kept up for liability reasons, that reference a time when Sioux Chief did not yet have the F1960 designation on their PEX-B product... just guessing here)... and also because I don't have the power expansion tool.
I want actual PEX-A, so I am likely going to special order it from Menards/HomeDepot/Lowes or order it from an online supply house like PexUniverse or SupplyHouse, but will make sure it's actually indicated as Peroxide or Engel method, and that I'm cross-referencing the proper UPC from a catalog indicating it's a PEX-A part.