40x40x20mm Super Strong Neodymium Block Magnet, N52 Permanent Magnet Disc, The World's Strongest and Most Powerful Rare Earth Magnets - One Piece

This is an interesting review because the number of stars for easy to remove and durability are both one. Normally, a one-star review is bad. But in this case, less starts is good news! Easy to remove would mean a weak magnet, and neodymium magnets are not durable. These are facts. The product advertisement on Amazon covers some of these points. But the question should have been "magnetic grip" and that would have been five stars. Complaining about a neodymium magnet being fragile is like saying an eggshell is fragile. It is the way it is. So, first off, you want powerful magnets? Order these. Good price, fast shipping, good product. You will get what you want. But there is more to the story. These are dangerous in even in experienced hands. I am experienced - and still had troubles. This is not the manufacturers or vendors fault. These are powerful magnets, and any difficulties are the responsibility of the user. Don't order these as toys. To avoid disappointment, you should know in advance exactly what you wish to do with these. I did know, and I had difficulties, because these magnets are so strong they are actually annoying!! I did not want multiple powerful magnets because of the need to avoid crashing magnets together which breaks them, creating sharp shards of metal, crushing fingers in the process. I knew I wanted a single magnet, to demonstrate the long distance effects of a powerful magnet. Other websites had what are probably better magnets at a similar price, but nobody could beat Amazon's shipping costs and time. So I bought four of these. They are shipped two to a small box, together, with a small spacer between them. I knew already I wanted these magnets stuck together into one big one. I knew I wanted to put them into a larger piece of metal to make handling easier and safer. When you order two, they come packed in the same box, separated by a piece of plastic and cushioned in styrofoam. Getting a magnet pair separated was difficult, but doable. I knew that bringing two pairs together in a controlled manner would be very difficult. Knowing that these magnets will accelerate towards each other in an instant, I put one pair outside the cardboard they shipped in, placed a magazine inside the box for extra spacing and cushioning, and brought them together. As expected, they flew together. But I could not move them enough to get the magazine out or slide them to the edge of the cardboard. The attractive force was so great the cardboard was compressed to nothing. I ended up cutting around the magnet outline, through the cardboard and the magazine. I decided to put the magnets into a vice, gripping the two lower magnets only. It took 20 minutes to get them properly oriented in the vice. Sliding and twisting the magnets required the use of a crowbar and vice grips. Using the bench vice and large water pump pliers, I was able to get enough separation to slide a wooden shim between them. Using the shim, I was able to get all the paper out between the magnet pairs, then slide the shim out, thus bringing the magnets together in a controlled fashion. This took another hour! I brought the four magnets into the house to tinker. From 18 inches away, a 3" diameter ceramic magnet, with a couple small disc magnets attached, slammed into my new big magnet. All three ceramic magnets broke and chipped my new big magnet. I was pretty confident 18" was enough separation. There is a very nice set of smart phone apps written by Keuwlsoft. Go to the play store, search for Keuwlsoft, scroll down and look for the "Gauss Meter." It is free, but you get ads. They are not bad, but I always buy the apps because I want to reward the creative minds that create these tools. The app turns the magnetometer inside your smartphone into a Gauss meter, allowing you to measure and quantify the intensity of magnetic fields. This Gauss meter picks up my new big magnet from a few feet away. Bringing the phone closer, hits the 45 gauss limit of the meter. It affects compasses and other magnets at a similar distance, which is exactly what I want to demonstrate to my students. 45 Gauss is a lot! The earths magnetic field average 1/2 a Gauss. Since I do not want to ever separate these magnets, I decided to put them into a protective metal sleeve. I used a 3" long piece of 2" x 2" x 1/8th" piece of square tubing. It was my intention to center the magnets in the tube by driving wooden wedges into place. The magnets had other ideas, and simply getting them into the tube required a hydraulic press. Driving a wedge between the magnet and the wall of the tubing was not possible, so I settled for putting wedges down the two remaining sides. See the photo. This magnet will serve my classroom demonstrations very nicely. The price is reasonable, shipping was free with Prime, and the two-day shipping time was fantastic. I urge you to pursue reading on magnet safety. Have fun, enjoy these, and be safe! +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++.......................................................................................................................................................................... +.3

Super strong! Works well. I used this to locate metal studs behind thick wood walls. Due to the depth of the wall, a magnetic stud finder wasn't quite up to the task. With these magnets, I was able to immediately find my studs. No question about it. Very strong so be careful when using. Easy to pinch your fingers!

I am no stranger to neodymium magnets. Been buying them for decades before they ever started showing up in consumer products. I can tell you confidently that these are uncanny in size and strength for their price. Not the strongest magnet size in the world, but absolutely the best bang for your buck, and well beyond the expectations of average consumers and most nerds and geeks. Nobody would ever call these weak magnets. You WILL require a mechanical aid to separate the two magnets even with the provided plastic spacer between them. I used the corner of a wooden table to sheer the two magnets apart using all of my body weight pushing down. IF you are an average consumer, then do not buy these, you will hurt yourself. If you do not wear eye protection while goofing around with them, you will go blind when they collide with each other and shatter into pointy shards in your face. Blindness is forever. You may even cut yourself and require an emergency room visit for stitches. But nevermind that, because you're still blind in both eyes. So sorry. I would recommend purchasing some 1.75 to 2" diameter heat shrink tubing to secure around each of the magnets, twice, to make them less likely to shatter if something collides with them, or vice versa. Neodymium magnets are extremely brittle and will shatter like a ceramic mug against a wrecking ball. Any bit of cushioning you can wrap around it will protect your investment, and your eyeballs, and your arteries. Oh yeah, it arrived in a 3-1/2 inch cube box. The box easily stuck to my fridge unopened. I'm sure the FedEx driver loved it!

CAUTION: I will still give these a 5-rating, because I do believe that they are every bit as strong as represented and a good value for what they are. However, every purchaser should be cautioned: if more that one magnet is used with another, you will need to be incredibly careful not to allow them to become closer than about 8”-12” to each other. If they are allowed to strike one another, you should expect one of or both to break, accompanied by a bright, startling spark. They are incredibly brittle. We experimented with our set for only 2 days before disposing of them for safety reasons. As for strength, they arrived separated by a plastic washer. Even so, they were very difficult to further separate using the instructed method of a table or counter edge. Without the washer it required most all of my strength to separate them.

Very strong magnets. But as other reviewers have stated, be careful with them. They lasted about 5 mins. While I was showing them to my daughter (my daughter loves science), I accidentally let them smack together (they were too strong for my fingers). This caused them to shatter a bit and cut my hand. Strong is an understatement for these. I wish they came coated in a silicon sleeve or something.

I was lost at first thinking I wasted money since I wanted this to open a yondr pouch from school, I thought using only one by itself would work but it didnt since the pouches got stronger and thicker this year. Just keep both magnets together and it'll generate enough strength to open the pouch after you hit it a few times, you don't have to hit it crazy hard but it will open after a few good hits.

Super strong magnets. I couldn't get them apart.

This magnet is extremely magnetic, nearly got my fingers pinched through the gloves when I was testing putting some tools on the magnet! Thankfully, I was wearing some thick gloves and prevented any bruising from happening from the pinch! I compared this to some fish magnets claiming to be "300 lbs" pull force and holy gawd this thing is even way stronger than that magnet! I suspect this might be because those fish magnets have a magnetic shield from their outer shell and the actual magnet is smaller than the shell itself. Anyway, this magnet is really thick even though it is small in your hands, this will literally crush fingers if not properly handled. A reminder when removing these 2 magnets apart though, do not let yourself be distracted after separating these 2 magnets apart. Once apart from each other put the one on the table far away from the one in your hand. If you do not do this it will fling itself to the other magnet and cause a powerful impact potentially breaking 1 or even both magnets, it may even pinch a finger! These types of magnets that are this powerful are known to be brittle and break easily if impacted by another magnet, so be in your best mind to follow precautions. Overall, this is a great magnet, helps me find screws, nails, and old tools that may be sticking out on the ground. Very useful and strong! Maybe sometimes too STRONG!

注意して取り扱わないと怪我をするレベルの磁力、指とかを挟んだら本当に危険！ 自分の使用用途には十分な磁力だったので大変満足。

Super strong be careful with your fingers. If they get stuck together it is nearly impossible to get apart.

These are stronger than I expected. I use them in high school science demonstrations and was very pleased. Do be careful though as they could pinch you, or smash together very hard and break if you are not careful.

These 2 magnets have a very strong attraction to each other. Had one in each hand and they pulled out my hands which were about 6 inches apart. They snapped together and broke. The outer coating is very thin. Not worth mailing them back for a refund. Beware of the manufacturer/seller.