The classic spiral stair with stainless steel central column can be finished with glass treads of course. Hereby the treads are either round at the side or angular, adjusted to the wall shape, if required. Besides this well know spiral glass stair type we have designed something very special. Our spiral staircase Sky-Screw is available as all-glass staircase and in wood and concrete. All of the options do not show steel elements. Usually the railing is curved glass, hanging from the ceiling. The exact shape of treads and finishing can be custom made to the requirements.