Aluminum - Pipe - Sch 40 - 6063-T52 Pipe (Extruded)
6063 is often called architectural aluminum for two reasons: first, it has a surface finish that is far smoother than the other commercially available alloys; and second, its strength is significantly less, (roughly half the strength of 6061), making it better suited for applications where strength is not the foremost consideration.
6063 is rated as "Good" for forming and cold working operations, "Excellent" for anodizing, and "Fair" for machining.