Common T-slot aluminum extrusion sizes include 10×10 mm, 20×20 mm, 30×30 mm, 40×40 mm, 45×45 mm, 50×50 mm, 60×60 mm, 80×80 mm, 100×100 mm, and 160×160 mm. These profiles are widely used for framing and assembly applications in industries such as windows, doors, and structural construction, though specific sizes may vary depending on the application.