Friction cutting (angle grinder, unless special aluminium discs are used, which are kind of like a wood saw, i.e. the cut as opposed to grind) will not work. The aluminium clogs and melts into the porus angle grinder cutting discs (which cut through steel happily through friction, not with a cutting edge)
This is why Aluminium can be cut with table saws and routers. It really is more like cutting wood than steel.
So....... for that thickness. yes, a industrial metal band saw will work (do not try and put round bar through a woodworking band saw, you will loose your fingers). The best would be a "cold saw" which is like a drop saw but very slow and the blades have sharp teeth. and lots of cutting fluid.
I assume parting off the short bits on a home lathe is not an option as 2-1/2" will not go through the throat of the chuck.
(Sorry for all the parenthesis!)