Bolted silos are mainly used to store large quantities of various bulk materials, in particular gravel, hardcore, chippings and non-metallic minerals. The silos are manufactured with standard diameters of 4,647 mm – 12,000 mm. Cone inclinations of 45°, 55°, and 60° are available. Bolted silos are mainly used to store large quantities of various bulk materials, in particular gravel, hardcore, chippings, and non-metallic minerals. The silos are manufactured with standard diameters of 4,647 mm – 12,000 mm.