Welding Expertise and Quality for Cloud Gate Sculpture


  • When Artist Anish Kapoor created Chicago's Cloud Gate, one of the world's largest public sculptures, Kapoor wanted to use a material that had a high degree of reflectivity, ease of fabrication and maintenance, and excellent resistance against the area's harsh environment (humid summers and winter snow removal remedies).
  • The material also needed to replicate the look of liquid mercury.


  • New Castle Stainless Plate had unique molybdenum steel plate products that could meet the mirror-like surface specifications that Kapoor was seeking. The material was highly resistant to corrosion and could be easily welded and fabricated. New Castle Stainless Plate specifically finished the plates with 0.002 percent maximum sulfur to achieve superior reflectivity.
  • New Castle Stainless Plate was selected for its superior metallurgical cleanliness and lack of slag inclusions, which helped ensure the smooth, mirror-like finish desired by Kapoor.
  • The largest stainless steel plates averaged seven feet in width, 11 feet in length, and weighed approximately 1,500 pounds each. A company in California fabricated each piece of plate into a precise curvature before shipping them to Chicago for assembly. New Castle Stainless Plate's exceptional flatness and dimensional tolerances helped guarantee that the plates would all fit precisely together as planned.


  • The New Castle Stainless Plate team was able to deliver the 168 pieces of stainless plate for this project within the specified timeframe.
  • The entire assembly process took two years to grind and polish the plates and an additional year to weld 2,500 lineal feet of seams between the plates. During this time, New Castle Stainless Plate experts provided consultation on the welding techniques to achieve the smooth, seamless and highly reflective finish specified for the project.
  • The sculpture has become a popular tourist location that reflects Chicago's Millennium Park and downtown skyline in its mirror-like finish that achieves the artist's vision of liquid mercury.