Which magnet should I choose?
Short answer: choose a magnet in this order: (1) what should it attach to: steel or a second magnet; (2) how will you attach it: screws, glue, adhesive, or clamping; that determines the shape; (3) how much strength do you need: allow a margin of 2 to 3 times, and 5 to 10 times on a vertical surface; (4) indoors or outdoors: that determines the coating; (5) will it get warmer than 80 °C. Choose the N-grade (N35 – N52) last: the size matters more.
Step 1: What should the magnet attach to?
- To steel (cabinet, beam, plate): one magnet is enough. For thick steel, a pot magnet is strongest.
- To another magnet (latch, lid, model building): use two magnets with opposite poles, or a magnet with a steel counterplate, such as a steel ring with a countersunk hole.
- Through a material (wood, glass, fabric): choose a thicker magnet. See can magnets work through wood, glass and plastic?
- To aluminium or stainless steel: it won't work. First glue or screw a steel plate on.
Step 2: How will you attach it? That determines the shape
| Attachment | Best shape | Selection guide |
|---|---|---|
| Gluing into a round hole | disc magnet | which disc magnet? |
| In a slot or on a straight edge | block magnet | which block magnet? |
| Screwing | magnet with countersunk hole or ring magnet | which ring magnet? |
| Deep mounting, narrow hole | rod magnet | which rod magnet? |
| Attaching with a bolt, hook or eye | pot magnet | which pot magnet? |
| Hanging | hook or eye magnet | hook / eye |
| Sticking to a smooth surface | self-adhesive magnet | self-adhesive magnets |
| Sewing into fabric | PVC sewing magnet | sewing magnets |
| Building, puzzles, memo board | cube or ball magnet | cube / ball |
An overview of all shapes is available in which neodymium magnet do you choose? Overview by shape.
Step 3: How much holding force do you need?
- Pulling straight on thick steel: choose a magnet with at least 2 to 3 times the weight as the stated holding force.
- On a vertical wall or door: the magnet will slide at 15 – 25% of its holding force. Choose 5 to 10 times the weight, or a rubber version.
- Through paint, foil or wood: allow an even larger margin; see the table in can magnets work through wood?
- Latch (door, lid): 0.5 – 2 kg per latch is usually enough. Too strong is also not good: then it will be difficult to open.
A table with holding force per size is available in how strong is a neodymium magnet? Note: holding force is not working load. See holding force, pulling force and working load.
Step 4: Indoors, damp or outdoors?
- Indoors, dry: standard NiCuNi coating.
- Damp or sheltered outdoors: epoxy.
- Outdoors in the rain: plastic coated.
- On lacquer: rubber.
More in can magnets be used outdoors?
Step 5: Temperature
Standard neodymium can withstand up to approx. 80 °C (N50 and N52 up to approx. 60 – 70 °C). Near lamps, motors or in a car in the sun, it can get warmer. See magnet at high temperatures.
Step 6: Then adjust the grade
N45 to N48 is a good standard. N50/N52 if space is limited; N35 if price is more important than size. See what does N35, N42, N48 and N52 mean?
Frequently asked questions
What is the best magnet for a cabinet door?
Two disc magnets Ø8 x 3 mm or Ø10 x 3 mm (approx. 1.4 – 2.1 kg), or a magnet with a steel counterplate. If you want to screw it in, choose ring magnets with countersunk holes: two magnets (north against south) or a magnet with a steel counter ring.
What is the best magnet to hang something from a steel beam?
A hook or eye magnet. Choose generously: a pot magnet that is loaded sideways will slide at a quarter of its holding force.
Can I ask for advice?
Yes. Use the Magnet Advisor or contact us with your application, the dimensions and the weight.
