SLICE METHOD AND DEVICE

PURPOSE:To prevent rupture accidents in advance and extend the service life of a blade by measuring magnetic flux in a magnetic circuit communicated with the inside of the blade, determining internal stress and warping, and operating the blade under the condition where tensile force, which corrects the warping, is given to the blade under the internal stress which fails to exceed an allowable value. CONSTITUTION:An internal stress calculation means, a warping calculation means, a tensile force imparting means 3 are provided on both sides where a blade 2 is clamped. Based on the sum of the detection results by each magnetic flux detection means of magnetic circuits 8R, 9R, and, 9L, the internal stress of the blade 2 is determined while warping is determined based on the difference. Proper force, which corrects warping within the range of internal stress which does not exceed its allowable value, is imparted to the blade 2, and then cut is performed. When a plurality of paired magnetic circuits are generated. The distribution of internal stress and warping can be grasped. When both warping and tensile stress to be given exceed their respective allowable value, the application of the blade under such condition, may cause to deteriorate the degree of evenness on the cut side. Therefore, it is necessary to stop the use of the blade.