In recent years, for the purpose of improving the fuel efficiency of engine vehicles and reducing the load on motors of hybrid vehicles and electric vehicles to reduce CO2 emissions, there has been strong demand for the weight reduction of vehicle bodies. Accordingly, the adoption of high-tensile strength steel sheets has been rapidly increasing. At the same time, demand for hard and thin electrical steel sheets is also increasing, as is the need for efficiency improvement and reduction in the size of on-board electric motors. In response to such demands from society, steel making companies need a rolling mill that can produce thinner and harder materials more efficiently. Primetals Technologies has developed HYPER UC-MILL (6-high rolling mill), which has work rolls 20-30% smaller than those of UC-MILL (6-high rolling mill), a leader in the cold rolling, to meet these needs. This mill achieves a higher level of shape controllability and lower load for rolls, features heavier reduction capability than that of the existing UC-MILL, and has the significant advantage of driving the work rolls despite their small diameter. To date, we have received orders for a total of seven HYPER UC-MILLs, three of which are already operating and four of which are currently being designed and manufactured. The mill is significantly contributing to the production of hard and thin materials (high-tensile strength steel and high-grade electrical steel sheets). This report presents the characteristics of HYPER UC-MILL, the effects of its use, and an example of its application to a tandem cold mill for the production of high-grade electrical steel sheets ordered from Shougang Qian' an Electric Vehicle Electrical Steel Co., Ltd. (China) in Jan. 2020.