Abstract: A flat-rolled metal product cutting apparatus comprises a support installed at the side of the travel line of a flat-rolled metal product, a first and a second chock attached to the support to rotatably support an arbor of a first and a second rotary knife, and a first and a second circular rotary knife, each having the shape of a cylinder or truncated cone, attached near the front end of each arbor. The two rotary knives are disposed in such a manner that the circular knife edges of the two rotary knives meet at the cutting point, with a slight clearance left therebetween, and the axis of rotation of one rotary knife is inclined in a plane containing the axes of rotation of the two rotary knives and also that two planes each containing the axis of rotation of each rotary knife and the cutting point are inclined with respect to each other. The paired circular rotary knives of the flat-rolled metal product cutting apparatus makes a cut along the length of the flat-rolled product that travels forward.