what is T45 tube made of? i have been on lots of websites and all i have gathered is that T45 is a type of tube (british standard) not a type of material. i really want to find a good data sheet of all the info about this material for finite ellement analysis. i need poisons ratio, ultimate tesile stress, yield stress, and youngs modulous. youngs modulous isnt such a problem since its the same for all steels but all i can find are values of similar materials such as 4130 steel for the others. i guess the figures i have got will do but i would still like to find a data sheet. i did find a site with some values for yield stress and ultimate tensile stress for T45 but it gave a range not a specific value which i find odd. does this mean the quality of the material varies? another value i would like to find out is the yield stress after welding but im not sure how to get this.