These drums are not the same quality as the ones that came with my Dremel. I had several of these before having to purchase this pack. I can use them on any material, be it smoothing or shaping wood or removing rust from old car parts. One will last until the sand is too caked with debris. I was hoping these drums would work as they should, but they don't. I made the tree out of 1/4" plywood. After making most of the shapes with a jigsaw, I switched to sanding drums for shaping and fine tuning. I use about 3-4 drums for every 6 1/4". Plywood edge. This is unacceptable. Sometimes I don't even get that far. I would try a new drum around a small corner and it would break almost immediately. And if you use a drum you know how uncomfortable it is to use gloves. I've tried light pressure, high pressure, high and low speed and nothing seems to have affected the drums' durability.