China Neodymium And Ferrite Magnets Manufacturer & Supplier 
20mm neodymium magnet (less than 1 inch) is a very popular and strong magnet size, which is used in many products, and it can come in so many shapes for us magnet manufacturers, here is a list of some of the common ones for you.
The first is round (disc-shaped), which is the most common, there is no hole on the surface, the diameter is 20mm, the thickness can be customized according to the needs of some customers in order to adapt to the structure or wiring may need to open a slot on the surface.
Pictures include 20mm neodymium magnets in various shapes
Bar (block) shape is also very common, 20mm generally refers to the length of the neodymium magnet, the width thickness can be customized according to the application, its magnetization needs to be specially described, generally the thickness magnetization, but also the length or width magnetization, such as used in reed switches or other applications.
Ring shape will not fall naturally, 20mm generally refers to the outer diameter of the ring magnet, say 20mm ring neodymium magnet will be more clear point, the size and thickness of the hole can be customized, you can also process the hole on the front or side.
Sample: Heat resistant 100℃ neodymium magnet ring 35M 20x12x8mm
Cylindrical shape relative purchase customers will be less, 20mm generally refers to the thickness of the magnet, the diameter size of 1-5mm is more common, according to the user of the magnetic force can be radial or axial magnetization.
Cube shape, 20mm is its length, width and height dimensions, suitable for fixing or component combinations in equipment.
Pot shaped with a metal shell wrapped around the outside, 20mm generally refers to the size of the steel shell included, and is generally used for salvaging, storing, and securing equipment.
Countersunk holes (screw holes) shape can be of the above and other shapes not mentioned, the size of the holes is usually M3, M4, with screws, can be installed on wood, metal and other surfaces.
Since we are talking about countersunk holes, there must be a straight hole shape, 20mm magnets with straight holes are different from ring magnets in that the straight holes can be of many shapes. Different positions, variable number, used to pass through some rods, shafts.
Above are some shapes of 20mm neodymium magnets often processed, each shape is suitable for different industrial or daily applications, the choice needs to take into account the magnetic field strength, shape, use of the environment and other special requirements, if you need to buy, customized special welcome to contact us.
Some product cases;
Square neodymium magnet with screw holes 20 x 20 x 5 mm
20mm dia stainless steel strong neodymium pot magnet china
1.5mm thick flat strong round neodymium magnet 20mm x 1.5mm
20mm x 5mm x hole 5mm black neodymium countersunk magnet ring