Review on Permanent Magnets Building Scientific Magnets by Russ Mashlan

First, I ordered them to put up signs to prevent others from throwing trash in our trash cans. They take and change these bins every week. I needed sign magnets so I could remove them and then reattach them when it was finished. These magnets looked like they would get the job done. The first thing I noticed upon arrival was that the top pair of magnets were broken into small pieces? So there is no solid metal, it is a composite material. They are similar in size to quarters in diameter and depth. Stacked on top of each other, they actually look like a stack of coins, not magnets. But as I said, some were broken. There I discovered how powerful they are. Trying to remove the fragments from the remaining magnets was by no means an easy task. FYI, due to their fragility, remember the 6 inch rule. If you can get two of these within 6 inches of each other, they will literally jump out of your hands to "grab" each other. So it is not surprising that small plastic partitions are placed between them so that they can be separated. Therein lies another problem. They do not come with adhesive already applied to the back. Instead they send some regular round glue tabs. Even if left for a while before installation, the magnets are too strong for the adhesive to hold when the item is removed. At most once I was able to remove the sticker before the magnets ripped off the adhesive tabs. just not a good design for magnets that are meant to be removed along with whatever they are attached to. The magnets that made it intact cannot be used as intended as the tape/adhesive strips will not hold. Therefore, I cannot recommend them due to their fragility and lack of adhesion to the sticky/sticky part. They're surprisingly strong magnets, but they have too many flaws for me. Others may like them, which is why I gave them three stars instead of two. FYI, Amazon's customer service has been great as always. I reported the broken magnets to them and the problem was fixed in less than five minutes. I appreciate that very much!