The availability of the unified estimation method for use with Slide Gate Plate was confirmed through our experiment； the fast fracture tests and the cyclic fatigue tests were carried out at room temperature and 1400℃ in an argon gas atmosphere．Only the fast fracture test was conducted at 1100℃，1200℃ and 1300℃ in this argon gas atmosphere．The following results were obtained．
（1）The unified estimation method was shown to be applicable for the strength evaluation of the complex material composition of a Slide Gate Plate．
（2）The temperature dependency of bending strength was observed at four temperatures from room
temperature through 1400℃．Bending strength decreased above 1300℃．
