A method for slitting sheet material having a thickness, a width, a leading edge and a shear strength. The slitter has rotatable arbors and knives on each arbor that rotate about their axes and are held adjacent to each other. A computer is used to calculate a first and second spacing for the arbors based on the shear strength, outer diameter, and thickness of the material. The material is inserted between the knives and the leading edge passes through the slitter with the arbors the first position that pinches the material between outer diameters of opposing knives as it moves forward. While the material moves forward the arbors are moved into a second and closer position in which the knives are situated to slit the material as it passes between the knives. This slitting of material behind the leading edge creates a leading tab holding the slit strips together.