Abstract: A method for positioning coacting circular cutting blades in a slitting device for a web of material characterized by moving the pair of blades which are mounted on separate carriages along rails extending transverse to the direction of movement of the web being cut to a predetermined position, and locking the carriages of the blades in this predetermined position with the method including compensating for changes in the width of the cutting blade due to sharpening and grinding by measuring the distance of the cutting edge of the blade from a bench mark on the carriage, comparing this distance to a standard to form an offset amount and using the offset amount to correct the amount of movement of the carriage so that the blades are positioned on the desired cutting line.