A foldable wire mesh cage (also called a warehouse cage, butterfly cage, or turnover cage) is mainly made of Q235 cold-drawn wire. The wire thickness follows the load, typically between 4.5mm and 6.4mm. The foot cups and the U-channel base are mainly K5235 low-carbon cold-rolled sheet. The U-channel is rolled on a cold-rolled strip mill, and the four bottom feet are formed by stamping. The foot cup, including the U-channel, stands about 140mm high, so a forklift and pallet truck can fork in easily. Surface treatment uses an eco-friendly trivalent-chromium galvanizing process, usually white zinc (cold galvanizing). Hot-dip galvanizing is arranged separately only when the order reaches about 500 pieces or more. In short: heavy loads call for a thicker wire (6.0mm and up), light loads for a thinner wire (around 4.8mm). Indoor standard use takes cold galvanizing; outdoor or damp environments take hot-dip galvanizing.