TubeWeld [India] Limited manufactures Carbon Steel Pipes and Tubes. TubeWeld [India] Limited supplies various types of industrial boiler plants. The Carbon Steel Pipes and Tubes are frequently used as manufactured in area with ASTM specifications A-106 & A-S3. The chemical compositions of these two materials are identical, both are subjected to physical test, but those for A-106 are more rigorous. A-106 Carbon Steel Pipes and Tubes are made in grade A & B. Grade B has higher strength properties but is less ductile and for this reason Grade A is permitted only for cold or close coiling. When carbon steel is intended for use in welded construction at temperatures in excess of 427 Deg C and its use in welded construction above this value should be with caution.