PURPOSE: To make it possible to machine a smooth connecting line section in a short time by cutting a roll in X and Y axes numerical control in the axis direction of the roll so as to form a complicated caliper groove and then make a cutting tool run at one time along a side relief section, groove sholder R section, caliper, and so on.

CONSTITUTION: The respective d.c. servo motors 5 and 6 for X and Y axes are numerically controlled to perform cutting for forming a specified side relief, groove sholder R, and a specified caliper groove on a roll. That is, a roll stand 2 is attached on an index table 1, and when a start button is depressed, the index table 1 slides on a slide base and stops at a machining position for connecting a roll shaft and motor shaft with a coupling 7. Then, the roll rotates automatically for being cut in its axial direction in X and Y axis numerical control. And when cutting is completed, a cylinder 8 and lever 9 work to remove the coupling 7 for rotating the index table 1 at 120°. Then, the next roll shaft is connected to the motor shaft with the coupling 7 to be rotated and then the roll face is machined.