External diameter
21,5 [mm] +0,1/-0,1
Aperture diameter for head of a screw
7,2 [mm] +0,1/-0,1
Internal diameter
3,6 [mm] +0,1/-0,1
Height
6,5 [mm] +0,1/-0,1
magnetizing direction along dimension
6,5
Grade
N42
Magnet type
Neodymium
Maximal hoisting capacity
4,6 [kg]
Coating
Nickel (NiCuNi)
Maximum working temperature
≤ 80 [°C]
Housing
rubber (TPV)
Weight
12 [g]
Performance parameters
Direction of magnetization along the height means that one circular surface of a magnet makes the N-pole, while the other – opposite – circular surface refers to the S-pole.
The pull force was measured by using metal sheet 10 [mm] thick, acting with perpendicular detaching force. With the force acting on the sliding off, the lifting capacity of the magnet will be 5 times smaller. The air gap comprised between the metal sheet and a magnet causes reduction in the pull force.
For flat magnets and magnets mounted in the open magnetic circuit working temperature may be insignificantly lower. For high magnets and magnets mounted in the closed magnetic circuit working temperature equals max. working temperature for a given material. Curie’s temperature is ~ 310°[C]. Temperature coefficient of remanence TK(Br: approx. ~0,12 %/°[C]. Temperature coefficient of coercivity TK(HcJ): approx. -0,6 %/°[C].
All the numbers quoted were obtained as a result of tests with one specific item in a room temperature and are intended to serve for comparison of practical magnetic properties of magnets offered by the shop.
Magnetic properties of material grade N42
remanence Br |
1,28 - 1,32 [T] |
coercivity HcB |
min. 923 [kA/m] |
coercivity HcJ |
min. 955 [kA/m] |
energy product (BH)max |
318 - 342 [kJ/m3] |
| Magnetic properties of a particular material, together with its shape, volume, max. working temperature and direction of magnetization have influence on practical magnetic properties of a magnet. |
Physical properties
Density |
~7,5 [g/cm3] |
Vickers’ hardness (HV) |
~600 [kg/mm2] |
Resistivity |
~144 [uOhm x cm] |
D21,5xd7,2/3,6x6,5/N42 - Neodymium magnet
This is a round magnet with hole, ring magnet, with hole for countersunk screw head.
It is a rubberised, rubber-coated magnet in a rubber casing. The rubber largely prevents the magnet from breaking during knocks and impacts.
The magnet has a chamfered hole for mounting using a screw or a screw with a pointed head.
It is a neodymium magnet, magnetised along the height. It has two poles, which means it is double-sided. It has been protected against corrosion by nickel plating. It has been manufactured to excellent dimensional tolerances. The maximum operating temperature is no more than 80 degrees Celsius. Neodymium magnets stick to metal surface. You can attached magnet to surfaces made of ferromagnetic materials.