In March 2000, Nucor Corporation, the pioneering company that perfected the world's first thin-slab caster, joined BHP and IHI to form Castrip LLC. The new company's goal was to finally bring the Castrip® technology to commercial reality.  Nucor also became the first licensee of the Castrip technology. On February 27, 2001, ground was broken in Crawfordsville, Indiana on the world's first Castrip facility. Construction and commissioning of the Nucor Castrip plant was completed in May 2002, and the plant is expected to be fully operational by the fourth quarter of 2002.

To further solidify its leadership role in thin strip casting, Castrip LLC formed a strategic alliance with the Industrial Solutions and Services Group of Siemens AG and Siemens Energy & Automation, Inc. in August 2001, making Siemens the exclusive supplier of core automation equipment and services to Castrip technology licensees. This agreement brought together Castrip LLC's expertise in thin strip casting with Siemens' expertise in mill automation.  BlueScope Steel Limited (formerly known as BHP Steel) was listed on the Australian Stock Exchange on 15 July 2002. The company adopted its new name of BlueScope Steel in November 2003. All together, the Castrip patent portfolios of both companies are considered to be the most extensive in this field of use. Nucor, BlueScope Steel, IHI, Siemens and Castrip LLC control more than 1,500 patents and patents pending worldwide related to the twin roll casting of steels. This enormous patent portfolio protects Castrip LLC licensees from illegal competitors.