I believe Shane hit the nail on the head.

There are other considerations beyond the yield point or the tensile strength alone. There is a reason why there are so many different material specifications and there are reasons why the engineer selects one specification and not another.

The steel manufacturer can use different means of developing the mechanical properties required such as using different rolling methods, different balances of chemistry, different raw stock, i.e., rimmed, capped, or killed steels, etc. These different factors will affect the ease of welding, ability to form it into different shapes by rolling, bending, extruding, etc., as well as corrosion resistance, ductility, toughness, and so on.

The proper selection of materials can be very involved. No substitutions should be permitted unless the owner's engineer has approved the substitution.

Best regards - Al