@china_stair_manufacturer: ✅Weld-free modular design, easy to install.Clean site, no noise disturbance. ✅Made of 304 stainless steel, anti-rust and corrosion-resistant. ✅Custom enlarged & thickened fixing bolts and nuts on top. ✅Pre-assembled in factory, video inspection before shipment.#stairs #stainless #factory #staircase #sprialstaircase