There are beveled, threaded, screwed and plain end pipe types. The ASTM A210 GR A1 Seamless Carbon Steel Tubes can be welded with ease with most conventional methods. Preheating is not required for welding. And post weld heat treatment is also not required. The SA210 Gr. A1 heat exchanger tubes are specially made for the heat exchangers. There are round, rectangular, square and U pipe types.ASTM A210 Gr A1 Carbon Steel Pipe/ Tubes - Koryo SteelASTM A210 Gr A1 Carbon Steel Pipe/ Tubes ASTM A210 Grade A1 Seamless Tube shall be made by the seamless or welding process with the addition of no filler metal in the welding operation.