Rexroth doesn't appear to have an easily accessed online drawing/model for that particular profile but if you look at this one, drawings/models can be downloaded. This other one suggests that the outer wall thickness of your chosen profile is 1.5 mm. For a first approximation, calculate the strength characteristics of a simple rectangular section aluminum tube, 45x90x1.5mm. To my eye, it looks like the Rexroth profile should be a bit stiffer/stronger than the simple rectangular box section.