Maybe we need to figure something out! I have used the blades and haven't had a problem. I am using a Fiskars rotary cutter. Maybe the blades don't fit certain cutters like Dawn Marie is asking! I did notice the center hole is completely round with no notches. I currently only have the harbor freight blades on hand so I can't check another blade, but I think I remember some sort of notch. I would request that if people say they have a problem with the blade, please say what brand cutter you are using. We might be able to find a pattern to why some of us love them and some of us hate them. It can't just be a random thing. Can it?