Yield Strength Rounds Down

Why does RAM Structural System round down the Yield Strength fy value?
I am located in Canada so if I use american steel then I convert the fy=50 000psi to MPa which is approximately 345MPa. So in the Modeler when laying out the beams I type in 345MPa, then in the Beam Design -> View/Update Beam it says Fy (N/mm2): 345, but when I go to View Results for a closer look it says Grade = 300W (corresponding Design fy=300MPa)?

Now if I use 350MPa it uses the proper yield strength so to me it appears as though there are thresholds which it automatically rounds down to if crossed.