I'm looking at a table of fatigue strengths for different steels. I would like to know what the figures mean. For instance, for S235 under streching/pressure it says [tex]0\pm160[/tex] and [tex]130\pm130[/tex]. I believe the values are supposed to be average tension pluss/minus amplitude tension, but I'm not sure. I'm hoping someone can explain this to me, and so maybe I can understand the Smith-diagrams soon as well.