This is a black square magnet with countersunk hole, it is made of rare earth neodymium, the specific size is 25mm in length and width, 13mm in thickness and the direction of magnetizing is thickness. This sample is plated black epoxy, it can extend the service life of the magnet, so that the magnet can prevent corrosion and oxidation. This magnet has a M4 contersunk hole at the center, this collocation is common when assembling certain large objects.
The choice of epoxy coating for neodymium magnets provides good corrosion protection, preventing oxidation and corrosion when the neodymium magnet comes into contact with air, water or other chemicals, which is particularly important for outdoor applications, wet environments or magnets exposed to chemicals.
If you have any requirment about magnet with M4 hole,please contact us and we can custom the quantity and place of hole for you!
Other size/shaped/material magnet with hole: