The Details：

Brief introduction of square magnet with hole:
Square dimension refers to the length (L) x width (W) x height (H) -D1/D2, usually with F heading to represent the square. For example: F30 * 20 * 3mm-D7.5/d3.5mm, said that the rectangular magnet is 30 mm long, 20 mm width, thickness of 3 mm (height), hole diameter 7.5mm, diameter 3.5mm straight hole general default a number that the last magnetizing direction of the magnet, F30 * 20 * 3mm square magnet that is, magnetizing direction for the 2 direction, which is the thickness (height) direction of magnetization. The N S is located on the two largest faces, i.e., 30 x 20mm, one side is N pole and the other side is S pole.
Working environment of 2. magnets:
In the selection of magnets, according to their working environment, should choose the appropriate grade of NdFeB, if the working temperature is higher than the temperature of the brand, the magnet will gradually demagnetization until no magnetic, before ordering must be sure that the working temperature and suitable for their own use of materials.
3. magnetic force and surface coating:
At present, the performance of N35 is widely used and the price is higher, if not in size changes to improve the magnetic force, we can improve the performance of materials to meet the product requirements, Eyre magnetoelectric also very advantageous in high performance materials the high magnetic properties, magnetic stability, and resolutely not low performance materials instead of high performance materials, surface coating: if less demanding on the surface, the general use of galvanized to protect the magnet, the magnet used if the environment is moist or salt spray requirements can take nickel plated copper plating nickel, epoxy, epoxy coating resistant to salt spray test 96 hours maximum.