The first industrial twin roll caster for carbon steel strips is under construction on the Nucor site at Crawfordsville. This installation based on the CASTRIP technology developed by BHP and IHI is expected to produce 500 000 tons per year of hot rolled strip with a thickness below 2 mm. In this paper the characteristics of the CASTRIP technology are presented, with reference to the economical aspects and further details on the main breakthroughs that had to be accomplished to improve the efficiency. The twin roll caster technology offers many advantages in terms of production costs, environment and production flexibility over more conventional production routes for carbon strips with a thickness below 2 mm. It is expected that the implementation of the new technology will foster the user demand for ultra thin gauge hot rolled strips.