Arc pattern spiral staircase steps are available in mild steel, aluminum and stainless steel materials and can be incorporated in all kit and fully assembled units. The arc pattern consists of 1/2" radial slots, rotating around the center column, complementing the natural radius of the spiral staircase. Although the arc pattern step would not be ideal for high heels, the 1/2" slots make it a great option for areas with snow and ice, and allows for stellar water drainage and traction. Arc pattern step is perfect fit for a spiral staircase application that doesn't want to sacrifice appearance for functionality.