This lovely white spiral staircase makes an attractive outdoor residential exit. The fully assembled 60 " diameter steel spiral staircase pictured is Stairways, Inc.’s most economical stair model, using square steel balusters, 1 1/2 " round steel handrails and pan-type steps. Many cost-effective customizable options available for this model. Fully assembled spiral staircases are seal welded and offer superior corrosion resistance, making these stairways perfect for outdoor applications.