Second-hand warehouse cages are cheap—roughly 30–50% of new ones—and are very tempting when the budget is tight. But the used market is murky: cages that look similar can be in wildly different condition. Buying used means you must know how to inspect; otherwise you bring home a pile of scrap iron that cannot be repaired.
The first step of inspection is to look at the structure. Stand at the side of the cage and see whether the posts are vertical, whether the four posts lie in the same plane, and whether there is obvious bending. Then look at the base frame; shake the cage by hand to feel for looseness or abnormal noise. Check the stacking feet and sockets for wear and deformation—these two parts are critical to stacking safety.
The second step is to look at the welds. Focus on the joints between posts and the base skeleton, the weld points between mesh and frame, and the weld seams of stacking feet. Tap welds lightly with a small hammer and listen: a crisp sound indicates a good weld, while a dull sound signals a cold or broken weld. If possible, load a batch and try one stack to see whether the cage deforms noticeably.
The third step is to look at rust and surface. Light surface rust and chipped paint do not affect use—grind and powder-coat and they are fine. But if pipe walls have already thinned with rust, rust flakes peel off when scraped by hand, or the base frame has rust-through holes, this cage's structural strength has already declined and must not be bought. Weighing for comparison also helps: a new cage of the same specification has a standard weight; if a used cage is markedly lighter, it means thinner material or rust-related weight loss.
Finally, tally the whole account. A used cage has a low unit price, but once you add repair, refurbishment and transport costs, it is sometimes not much cheaper than a new cage. Nanjing Tongnuo Warehouse Equipment Manufacturing Co., Ltd. recommends: if your purchase volume is under ten units, just buy new cages—you get warranty and after-sales service; if the volume is large and the budget is truly tight, used cages can be considered, but on-site inspection is mandatory.