A helical staircase is often referred to as large staircase, leading upward in a flowing arc. These staircases are installed in places where space required is large. It is possible in large curve, straight and large Square. Due to its design these staircases are more suitable for Retail Outlet, Showrooms, Malls, Restaurants, & Industrial Areas. They consist of two rolled stringers, with treads attached between them. Stringers are made by using Box Plate, Single Plate, ISMB, ISMC.