Set of 4 magnets Size: 3/4" diameter x 1/8" thick. (19.1 mm x 3.2 mm) Material: Neodymium (NdFeB) Grade: N48 Coating: Plastic Magnetization: Axial SKU# M34x18plasDI South Pole side is RED & North Pole side is GREEN What are the advantages and disadvantages of plastic encased magnets? One of the biggest drawbacks to Neodymium magnets is though very strong, they are very fragile. Tough coatings, such as nickel, go a long way toward protecting the magnets from cracks and breakage. However, after repeated impacts with each other or other surfaces, even the best metal coatings will fail. Plastic coatings offer impact and corrosion protection solution to the fragile magnets inside. These magnets can sustain far more punishment than the typical metal coated magnets, making these a good play or experimention magnet. However, on the negative side, this relatively thick coating reduces the effective power of the magnet. due to the logarithmic drop in magnet strength as the distance increases from the surface of magnet. How much off a difference? 2 standard nickel coated 3/4 x 1/8" N48 disc magnets will pull at each other with about 9 pounds of force. Two 3/4 x 1/8" N48 plastic coated will only pull with about 5 pounds of force. That is 45% less strength. So it is a tradeoff. If you require maximum power, go with metal coated. If longevity is what you need, try these plastic coated magnets. NEODYMIUM MAGNETS ARE NOT SAFE FOR CHILDREN
