To optimize a dimension by eliminating a waste of fatigue strength and yield strength of a cross pin and a fastening bolt while securing a prescribed life of a bearing roller in a spindle for a rolling mill to which a torque transmitting system capable of setting a torque interruption setting torque at a low value is applied.

In a spindle for a rolling mill wherein a cross kid part 103A provided in an intermediate shaft 124 is provided witch a case 118 which is fixed to the intermediate shaft 124 via a fastening bolt 116, a cross pin 112 which is rotatably attached to the case 118 via a bearing roller 14, a case 117 which rotatably supports the cross pin 112 via a bearing roller 113, and a fastening bolt 115 which fixes the case 117 to a counter intermediate shaft side member, when the diameter of the cross pin 112 is expressed by (d), the width of the bearing rovers 113, 114 is expressed by 1W, a distance from the center of the cross pin 112 to the center in the width direction of the bearing rollers 113, 114 is expressed by L, and the diameter of the cases 117, 118 is expressed by D, this spindle is constituted so as to satisfy the formula, d.1W.L/D3>0.018.