Cuplock horizontals, including ledgers and transoms, are made of 40 mm NB tubes and are so robust that they require zero maintenance. Horizontal tubes have forged blade ends that allow simple and quick assembly. The blade ends of the horizontals fit into the cup of the vertical tube, ensuring a strong assembly. Normal horizontals can also serve as guardrailings in a staircase tower. MS round pipes of 48.00 mm OD and 3 mm thickness are used. Minimum projection of blades avoids damages in handling, and uniform dimensions make the cup joints rigid.