There is alot more to the subject than is commonly discussed. The following is copied from GF web site Aka Uponor, explaining just one benefit of pex-a vs others: When comparing the Uponor PEX-a plumbing system with PEX-b and F1960 systems, it is important to look at the expansion rings. Uponor ProPEX expansion rings are extruded for maximum strength and capitalize on the shape memory of PEX-a to ensure a secure connection. Molded PEX-b rings eliminate the benefits of strength and shape memory for a connection that could be compromised.
My take on this is that astm f1960 does not equal pex-A, ASTM F1960 is a standard specification for cold expansion fittings (and PEX reinforcing rings) used with cross-linked polyethylene (PEX) tubing — and also PE-RT tubing in some cases. It defines the requirements for making expansion-style connections in hot/cold water distribution systems. PEX-A, on the other hand, refers to a specific type of PEX tubing manufactured using the peroxide (Engel) method, which gives it the highest degree of crosslinking (typically 70-85% or more), excellent flexibility, shape memory, and the ability to recover well after expansion.
