Steel blade with no sharp edges to swiftly saw cardboard, not fingers. Best of all, the cut edge of the cardboard is softened to eliminate those pesky cardboard paper cuts. We don’t call it the SAFE-SAW for nothing! How to use the SAFE-SAW: Reverse the tool to punch holes as a cutting guide-line if you need. The graded serrations allow you to easily saw any thickness of cardboard with a forward and backwards motion.