Flame Straightening means an eliminating of courses and tensions as a deforming of construction units by local heating up with oxygen acetylene flame. This procedure can be accomplished with the most metallic materials ( e.g. steel, stainless steel, aluminum ) and finds particularly in the steel structure, shipbuilding, tank construction, tubing`s building, mechanical engineering ect. its application. During flame straghting it is important to create an expansion handicap with tools or aids at the construction unit. It exists in addition the possibility with certain construction units through determines the neutral zone or with the weight of the own construction unit in the correct position ( situation of the construction unit ) the expansion to obstruct, so that it makes very purposefully and differentiated those for warming and high success when flame straightening obtained. With the establishment of a correct welding sequence the courses very small held so that the flame straightening also can be unnecessary.