No, but aluminium extrusions are widely used for window frames and glass sliding doors. So glass and aluminium often go together. I asked first at the hardware store and they refererred me to the glass place.....but you said "glass" shop.......is "glass" slang for aluminium?
Hollow bar is much cheaper than solid bar. The manufacturing costs are similar but the solid bar uses much more metal.I am extremely intrigued that extruded hollow square aluminium bar could be as cheap as "solid bar" aluminium.