TWIN-ROLL CASTING MACHINE

Provided are a pair of chilled rolls 1 on which molten steel solidifies for delivery of a steel strip 3 from a nip G between the rolls, a noncontact type sensor 6 for measuring thickness distribution of the strip 3 widthwise of the strip, marking means 8 for making a mark 7 on the strip 3 whenever the chilled rolls 1 make one rotation, mark detection means 9 for sensing the marks 7 on the strip 3 and nip estimating means 10. From thickness-distribution information 12 by the sensor 6 and passed-mark information 13 by the mark detection means 9, the nip estimating means 10 calculates variation of the nip G between the rolls 1 whenever the rolls make one rotation, on the basis of variation in thickness distribution widthwise of the strip 3 between confirmed passing of the mark 7 and confirmed passing of the next mark 7, and stores the same as data.