Brass 'I' beam.
These brass 'I' beams are used on architectural model making and design engineering projects.
Cut using a circular saw or manually with a hacksaw. If you don't want to solder, best joined using a two part epoxy or superglue.
Brass forms a greyish-green layer on the surface, which you should remove (sand, polish) before soldering.
After polishing, to preserve the shine, apply a clear laquer to the surface.
Our Workshop staff use Hycote Clear Gloss on their brass etching work.