Is SA213 T11 stainless steel? SA213 T11 is not a "stainless steel." It is a low alloy steel grade used in high-temperature services like boilers and heat exchangers. It's part of the ASTM A213 standard specification for seamless ferritic and austenitic alloy-steel boilers, superheaters, and heat-exchanger tubes. SA213 T11 is known for being solid and durable at high temperatures. It is also known for being very strong against thermal fatigue…