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 force, not the length. Below you will find which diameter is suitable for each application, the difference between axial and diametrical magnetisation, and what to pay attention to when installing it. All rod magnets are made of neodymium. Want to calculate how much holding force you need? Use the calculator further down or the Magnet Advisor.
Quickly choose by application
| Application | Usually suitable for | Example |
|---|---|---|
| Modelling, displays and electronics | Holding force up to approx. 1 kg | Ø3 x 10 mm |
| Small latches and flaps, installation in enclosures | Holding force approx. 1 to 3 kg | Ø6 x 20 mm, Ø8 x 15 mm |
| Cabinet doors, furniture and interior construction | Holding force approx. 3 to 8 kg | Ø10 x 30 mm, Ø12 x 50 mm |
| Sensors and rotating applications | Diametrically magnetised | Ø10 x 50 mm, Ø8.9 x 50 mm |
This is a guideline. Always test with one or two magnets before ordering a large batch or installing them.
Calculate how much holding force you need
Enter the weight, the number of rod magnets and the surface. The calculator shows the minimum holding force required per magnet and displays suitable rod magnets from our range. It is a guideline: always test with one or two magnets.
Choose by diameter, not by length
The holding force of a rod magnet is mainly determined by the flat end. A longer rod is therefore barely stronger: our Ø6 x 10 mm holds approx. 1.6 kg, the Ø6 x 40 mm approx. 1.7 kg. If you need more holding force, choose a larger diameter. Choose the length based on the space you have, for example the depth of the hole in which the magnet will be placed.
- Ø2 to Ø4 mm: approx. 190 g to 760 g. For modelling, electronics and small parts, for example Ø4 x 10 mm: approx. 740 g.
- Ø5 to Ø6 mm: approx. 1.2 to 1.7 kg. For small latches and flaps, for example Ø5 x 20 mm: approx. 1.2 kg.
- Ø8 mm: approx. 2.8 to 3.2 kg. For cabinet doors and latches in furniture construction, for example Ø8 x 15 mm N52: approx. 3.2 kg.
- Ø10 to Ø12 mm: approx. 4.4 to 7.4 kg. The strongest rod magnets we supply, for example Ø12 x 50 mm: approx. 7.4 kg.
Axially or diametrically magnetised
For most rod magnets, the poles are at the flat ends (axial). This is the correct choice if the magnet needs to pull against steel or another magnet with its end, for example in a drilled hole.
For diametrically magnetised rods, the poles are on the long sides. This is useful for sensors and rotating applications, because the magnetic direction rotates with the rod. Examples are the Ø10 x 50 mm and the Ø3 x 6 mm in the colours silver, rose, gunmetal black and black epoxy. Pay attention to the polarity during installation; if in doubt, contact us.
What to pay attention to
- The holding force 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 force is determined. Always test.
- Installation. If the rod fits tightly into a hole, take small dimensional tolerances into account. Glue the magnet with a suitable adhesive if it must not move.
- Quality (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 up to 80 °C. Above this temperature, the magnet can permanently lose strength.
- Jewellery. The NiCuNi layer contains nickel. Set the magnet into the jewellery 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; in this case, seek medical attention immediately. Keep strong magnets away from pacemakers, electronics and bank cards.
