Standing in Chicago's Millennium Park is a world-renowned stainless steel public artwork — Cloud Gate. Designed by British-born Indian artist Anish Kapoor.
Locals affectionately call it "The Bean."
Kapoor described his vision: "What I wanted to do in Millennium Park is make something that would engage the Chicago skyline — so that one will see the clouds kind of floating in, with those very tall buildings reflected in the work."
The work was inspired by liquid mercury.
I. Construction Process
Cloud Gate is supported by an internal stainless steel pipe truss system. This system includes two large O-shaped rings at the north and south ends, connected by intersecting pipe trusses.
The exterior is assembled from 168 panels of 316L stainless steel. Each panel was CNC-formed at a factory before being transported to Chicago for assembly.
All panels were joined by welding. The total seam length is approximately 744 meters. Welding was performed outdoors, with workers adapting to various challenging angles caused by the sculpture's curved surfaces.
In 2007, the American Welding Association awarded Cloud Gate its "Industry Outstanding Achievement Award."
After welding, the surface underwent multiple stages of grinding and polishing to achieve a mirror finish. The entire polishing process took approximately two years.
II. Public Reception
Chicago Mayor Richard M. Daley declared the unveiling day "Cloud Gate Day."
Time magazine called it an "extraordinary artwork" and a "tourist magnet."
Since its opening, Cloud Gate has become one of the most visited landmarks in Chicago.
III. Why It Matters for Stainless Steel Professionals
For those in the stainless steel industry, Cloud Gate demonstrates the unique possibilities of this material:
Mirror reflection — precision-polished stainless steel can achieve near-perfect reflectivity
Weather resistance — 316L stainless steel can withstand long-term outdoor exposure without rusting
Structural capability — stainless steel pipe truss systems can support enormous loads
Furthermore, the internal support structure of Cloud Gate relies heavily on stainless steel welded tubes. This represents a high-end application for our industry — serving as the invisible backbone of large-scale curved structures, providing both strength and durability.
