ASTM SA213 T11 boiler tubes are made of seamless ferritic low alloy steel and are used for boiler elements and heat exchangers. SA213 T11 is under the UNS designation K11597. There are two types of SA213 T11 steel: HF (hot finished) and CD (cold drawn), and all types must be tempered. It has a Rockwell B hardness of 85 HRB (Hardness Rating) and is in the P4 group of hardness.
