Magnet advisor

How much adhesive force do you need?

The Magnet Advisor calculates how much adhesive force per magnet you need, based on the weight, the number of magnets, the direction in which the weight pulls, and the surface. It then displays suitable neodymium magnets from our range, the cheapest first. This advice is a guideline: always test with one or two magnets before ordering a series.

The calculation is: weight divided by the number of magnets, multiplied by a margin, divided by a factor for the direction and a factor for the surface. The stated adhesive force is a laboratory value, measured on a flat, thick steel plate. Read how adhesive force is determined.

Guideline per application

Application Adhesive force per magnet Example
Model making, electronics, and small closures up to a few kilos Disc magnets
Cabinet doors, hatches, furniture making, camper and caravan approx. 4 to 10 kg Block magnets
Workshop, tools, molds, and heavier panels approx. 10 to 25 kg Block magnets, disc magnets
Industry and mechanical engineering from approx. 25 kg Pot magnets

Frequently asked questions

How much adhesive force do I need for my application?

Divide the weight by the number of magnets and include a margin. If the weight pulls perpendicularly from the steel, the stated adhesive force is the starting point. If the weight can slide along the surface, for example tools on a steel wall, often only a small part of the adhesive force remains. Use the Magnet Advisor above to calculate this.

Why does a magnet hold less than the stated adhesive force?

The stated adhesive force is measured under ideal conditions: a flat, thick steel plate and direct contact. In practice, paint, rust, dirt, an air gap, and thin sheet steel reduce the force. Read how adhesive force is determined.

What is the difference between perpendicular pulling and sliding?

With perpendicular pulling, you have to pull the magnet away from the steel. With sliding, the magnet glides along the surface. Sliding requires much less force, because only friction holds the magnet back.

What influence does the surface have?

Thick, clean, bare steel provides the best adhesion. Thin sheet steel, a layer of paint or powder coating, rust, and an air gap reduce the force. When in doubt, choose a magnet with more adhesive force or use more magnets.

How many magnets do I need?

Distribute the weight over multiple magnets and place them spread out so the object does not tilt. The advisor calculates what is needed per magnet.

Which shape fits my application?

A disc magnet is round and versatile. A block magnet has a flat contact surface and fits well in slots and against flat surfaces. Read Which disc magnet should you choose? or Which block magnet should you choose?.

What should I know about the north pole and south pole with a countersunk hole?

For versions with a countersunk hole, it is stated which pole is on the countersunk side. If two magnets must attract each other, combine a north pole variant with a south pole variant. Read more in the block magnet guide.

Is your application not listed? Contact us.