These were an experiment for me as I rarely go past 600 grit. Gotta say I've been impressed with these. They perform well with steel provided you take your time with progression and actively manage the heat. I also had a bit of a play using these with hardwoods. The finish on a slack belt was great but I reckon they'd glaze up too quickly with wood to be practical. All around great belts though, even if Idon'tsee them being part of my progression going forward.