depth becomes greater than 10 mm preferably the groove depth should lie between 3 and 7 mm and as a rule should be 5 mm the laser beam 12 should act on the surface of the roll 10 over a width of at the most 1 mm preferably 0 3 to 0 7 mm as a rule the laser beam should vaporize the material of the roll surface over a width of 0 5 mm and thus generate a groove width of 0 5 mm by the displacement of the roll in the axial direction the lateral distance between two adjacent groove channels is defined the maximum axial displacement velocity of the roll 10 should not form a distance between two adjacent groove channels 18 greater than at most 10 mm preferably about 5 mm of course the groove depth can also be set in the intensity of the laser beam 12 is increased or decreased while the roll 10 is rotated with constant velocity all the movements may be performed solely by the roll 10 or alternatively solely by the laser or laser beam preferably the roll 10 will execute the rotational movement while the laser beam 12 or laser source 14 will execute the axial movement along the axis of the roll 10 fig2 shows a schematic basic illustration of the arrangement according to fig1 but in plan view the helical path of the groove 18.