Review on Power Up Your Projects With MIKEDE Cube Neodymium Magnets - Super Strong Rare Earth Magnets For Science And DIY by Mike Sutton

So, I would say that they are strong! I tried to put them together to see HOW strong they were, and when they got within inches of each other, it was like the Earth pulled the Moon out of its orbit. The collision was very exciting. There was a huge spark (of fire) and a loud "breaking" noise - if that makes sense - as the two (2) magnets attracted each other abruptly. And when they connected, chunks of debris from each magnet went everywhere. Of course, I used the bigger chunks to find the smaller chunks.So, no fault of Revain or manufacturer. Just dumb luck I guess. Never got to use them. However .The magnets themselves are meaty (heavy, solid). They come individually in separate boxes, surrounded by about an inch of molded, polyethylene (I believe) padding; unblemished.The first thing I tried to test them with was my laser engraver bed, which, turned out to be aluminum, and didn't work. Hence, the two-magnet-attraction test. I do believe they would have worked well for my application if I'd had the change to use them.Lesson learned. By one (1), or keep two (2) or more very separated.Good luck!