1.1 ,This specification covers average or minimum-wall thickness welded tubes made from various grades of austenitic, ferritic, martensitic and duplex stainless steel materials in which the (1) external tube surface, (2) internal tube surface, or (3) both internal and external tube surfaces have a textured configuration for improved heat transfer or fluid flow or both. Texture surface(s) are produced by cold forming a specified configuration on the surface(s) of base strip material, prior to welding. The produced welded textured tubes may be used in boilers, superheaters, condensers, evaporators, heat exchangers, and other similar heat transfer apparatus in diameters up to and including 1.5 in. [38 mm] for various wall thicknesses up to and including 0.079 in. [2 mm].