Review on Enhance Your Woodworking Craftsmanship with Yakamoz Industrial Engraving Signmaking Tools by Darth Naubert

I am cutting shallow grooves in a new pine board and the durability of these knives is not very good. They probably weren't that great when I bought them new, but since I cut softwood I figured they would last a long time. Smoked 5/16 after a few cuts. The 3/8 was slightly better, but the other two were fine. If you use them in hardwoods or need them for long term use I would spend more for better quality bits.