I thought steel was steel. i.e. 7850 kg/m3 or around about.
In Egypt, do you use international sections or are there specific Egyptian ones? What section are you modelling? If it's not in the Robot database you are defining ALL steel sections for example?
Even if you do manually define a section, then self weight is going to be OK because the program recognises the cross sectional area. The only thing you may need to create is user defined materials (but can't imagine why), and this is pretty easy.
In summary......
If the bar exists in the database, the self weight is OK and depends on the material assigned.
If you define your own sections, the self weight is OK and depends on the material assigned.
Sorry if I misunderstood the problem
