Abstract: A roll profile measuring method uses a displacement detector mount provided movably in a reciprocating manner along an axial direction of a work roll, and a displacement detector set of two displacement detectors mounted at a center distance L.sub.c from each other on the displacement detector mount for measuring irregularities in the surface of the work roll in the axial direction of the work roll. The roll profile measuring method comprises: measuring irregularities in the surface of the work roll over the total length of the work roll by moving the displacement detector mount in the axial direction of the work roll; and processing a data stream of composite measured values obtained on the basis of the difference between measured data provided by the displacement detectors to determine the surface profile of the work roll in the axial direction of the work roll.

Abstract: The disclosed method and apparatus measures radial deviations along the axial length of a work roll with a number of axially spaced displacement detectors and at least three axially spaced motion detectors mounted ona detector mount that moves axially along the roll. A calculator responds to the motion detectors to determine errors in the motion of the mount to correct the output of the detectors and sums the deviators to generate overall deviations.

Abstract: A method and apparatus for grinding a roll in a rolling mill on an on-line grinding basis, are improved in that a freely rotatable grinding body such and is a grindstone is pressed against a surface of the roll to be ground as directed in the direction making a predetermined angle with respect to the axis of the roll. The roll is rotated so that the surface of the roll may be ground by a relative slip between the grinding body and the roll caused by their different circumferential velocities.