spiral-stair-11-thread-55-inch-diameter- spiral stair design 3D model

The staircase is a 55-inch diameter. It is designed to handle high traffic areas. The 11 treads plus additional landing platform provide a comfortable walking space while the single railing with continuous steel handrail ensures safe access up and down the staircase. - Can achieve height of 80-5/16 to 110-1/2 inches - 2 vertical steel balusters per tread - Can be installed in either a clockwise or counterclockwise direction - Can be installed with 9, 10, or 11 treads + platform