Which bar magnet do you choose?
Which rod magnet is right for your job? An overview by application and diameter, with explanations of axial and diametrical magnetization, length versus holding power, and what you need to keep in mind for installation.
For a rod magnet, the diameter determines the holding power, not the length. Below, you can read which diameter is suitable for each application, what the difference is between axial and diametral magnetization, and what you need to pay attention to during installation. All rod magnets are made of neodymium. Do you want to calculate how much holding power you need? Use the calculation tool at the bottom of this page or the Magnet Advisor.
Quick selection by application
| Application | Usually matches | Example |
|---|---|---|
| Model making, displays, and electronics | Holding power up to approx. 1 kg | Ø3 x 10 mm |
| Small latches and hatches, installation in housings | Holding power approx. 1 to 4 kg | Ø6 x 20 mm, Ø8 x 15 mm |
| Cabinet doors, furniture construction, and interior design | Holding power approx. 4 to 10 kg | Ø10 x 30 mm, Ø12 x 50 mm |
| Sensors and rotating applications | Diametrically magnetized | Ø10 x 50 mm, Ø8.9 x 50 mm |
This is a guideline. Always test with one or two magnets before ordering a large series or installing them.
Choose by diameter, not by length
The holding power of a rod magnet is primarily determined by the flat end. A longer rod is therefore hardly any stronger: our Ø6 x 10 mm holds approx. 2.0 kg, while the Ø6 x 40 mm holds approx. 2.2 kg. If you need more holding power, choose a larger diameter. Choose the length based on the space you have available, for example, the depth of the hole in which the magnet will be placed.
- Ø2 to Ø4 mm: approx. 0.24 to 1 kg. For model making, electronics, and small parts, for example Ø4 x 10 mm: approx. 950 g.
- Ø5 to Ø6 mm: approx. 1.4 to 2.2 kg. For small latches and hatches, for example Ø5 x 20 mm: approx. 1.5 kg.
- Ø8 mm: approx. 3.4 to 4.0 kg. For cabinet doors and latches in furniture construction, for example Ø8 x 15 mm N52: approx. 4.0 kg.
- Ø10 to Ø12 mm: approx. 5.4 to 9.1 kg. The strongest rod magnets we supply, for example Ø12 x 50 mm: approx. 9.1 kg.
Axially or diametrically magnetized
With most rod magnets, the poles are at the flat ends (axially). This is the right choice if the magnet needs to pull against steel or another magnet with its end, for example in a drilled hole.
With diametrically magnetized rods, the poles are on the long sides. This is useful for sensors and rotating applications, because the magnetic direction rotates along with the rod. Examples are the Ø10 x 50 mm and the Ø3 x 6 mm in the colors silver-colored, rosé, gunmetal black, and black epoxy. Pay attention to the pole direction during assembly; if in doubt, please contact us.
What you need to pay attention to
- The holding power is a laboratory value. It is measured on a flat, thick steel plate. In practice, the actual force is lower, especially with a thin, uneven, or coated surface or if there is an air gap. Read how holding power is determined. Always test.
- Installation. If the rod fits tightly in a hole, take into account small dimensional tolerances. Glue the magnet with suitable adhesive if it should not move.
- Grade (N35, N48, etc.). A higher number means a stronger magnet of the same size. Read what N35, N42, N48, and N52 mean.
- Temperature. Our rod magnets are suitable for use up to 80 °C. Above that temperature, the magnet may permanently lose strength.
- Jewelry. The NiCuNi coating contains nickel. Conceal the magnet within the jewelry so that the skin does not come into contact with it.
- Safety. Magnets are not toys and should be kept out of reach of children. Small rods can be swallowed; seek immediate medical help if this happens. Keep strong magnets away from pacemakers, electronics, and bank cards.
