Abstract: A durable male slotting blade for creating cleanly sheared slots in corrugated cardboard. The male slotting blade is adapted to be mounted to a slotter head of a cardboard box fabricating machine, and is provided with a cutting surface having first and second sets of serrations. A first set of serrations is provided on one side of the cutting surface while a second set of serrations is provided on an opposing side of the cutting surface with a valley formed therebetween. The first set of serrations are provided offset from, or out-of-phase with, the second set of serrations to provide for a cleaner cut with less frayed edges. Each of the serrations includes a peak and a valley machined not only into the sides of the cutting surface but also down into the valley formed in the cutting surface such that as the blade encounters abrasive recycled fibers, and is worn away, a new cutting surface is repetitively provided to thereby result in a longer lasting and more durable blade.