FAQ - Frequently Asked Questions
Should I buy a ferrite or neodymium magnet?
Table of Contents:
That depends on how you intend to use the magnets. Below some assistance:
We especially recommend ferrite magnets for the following circumstances:
- Tight Budget
- High Temperatures (80-250 ░C)
- Outside use
- Low aesthetics required
We especially recommend neodymium magnets for the following circumstances:
- Very high adhesive force required
- Limited space (miniaturisation)
- Little weight required
- Decoration/gift (nice coating)
Features of the materials neodymium and ferrite
|Adhesive force per volume|
|Outdoor use/rust resistance|
|Loss of adhesive force over time|
|Coercive field strength|
|Danger for children (swallowing)|
|Danger for devices|
Quick facts about magnet features
Adhesive force per volumeFerrite magnets are much weaker than neodymium magnets of the same volume (see Are your super magnets really the "world's strongest"?). Neodymium is therefore the preferred material when you have little space available and the end product needs to be fairly light (miniaturisation).
Same volume, different adhesive force:
Different volume, comparable adhesive force:
|R-27-16-05-N||1,8 cm3||8,3 kg||14 g|
|FE-R-80-40-15||56,5 cm3||9,5 kg||270 g|
PriceOn the one hand, ferrite material only costs a fraction of the NdFeB material. On the other hand, a neodymium magnet has an adhesive force that is about 8 to 10 times higher than that of a comparable ferrite magnet. If you calculate the cost per kg of adhesive force, ferrite magnets are about 2 to 3 times cheaper than neodymium magnets. This is especially true for block or ring magnets and for larger quantities. (With disc magnets the price per kg of adhesive force is comparable.)
The cost advantage is only then relevant, however, if weight and size do not matter, because the ferrite magnet is much heavier and larger than a neodymium magnets with the same adhesive force.
Price stabilityFerrite magnets are less subject to price fluctuations than neodymium magnets because their production does not require rare earth metals.
Temperature resistanceFerrite magnets can be used at temperatures between -40 ░C and 250 ░C, while most neodymium magnets lose their magnetisation permanently at a temperature of 80 ░C. However, temperatures under -40 ░C are no problem for neodymium magnets.
More information under What temperatures can magnets sustain?
Outdoor useFerrite magnets are chemical and rust resistant, while neodymium magnets are not suitable for outdoor use (except for rubberised Nd magnets).
More information under Can I use magnets outdoors as well?
BrittlenessFerrite magnets can break into pieces when you repeatedly put a strain on them. Neodymium magnets are very brittle and crack easily, which can lead to injuries of user or bystanders.
More information under Warning about splinters
Loss of adhesive forceNeither ferrite nor neodymium magnets lose their magnetisation by itself. They can only be demagnetised by external factors like heat or strong external magnetic fields.
More information under Does a magnet weaken over time?
Standard tolerancesNeodymium magnets generally have a tolerance of +/- 0,1 mm.
It's more complicated with ferrite magnets: Their height-related standard tolerance is +/- 0,1 mm; their width- and length-related tolerance is 2%, but at least 0,1 mm.
TransportSmaller ferrite magnets have a rather weak magnetic field and can be shielded quite easily. It requires much more effort to shield neodymium magnets in order to send them.
More information under Can I airfreight magnets?.
Ferrite and neodymium magnets should always be transported at a distance of at least 22 mm (we recommend 30 mm). Otherwise, neodymium magnets can demagnetise or even reverse the polarity of ferrite magnets (see table below).
Coercive fieldStronger neodymium magnets have the power to demagnetise or even reverse the polarity of ferrite magnets (see table below).
These minimum distances between the various magnet types have to be adhered to when it comes to use, storage and transport:
|Ferrite||Neodymium||AlNiCo||Sheets and tapes|
|Ferrite||-||22 mm||0 mm||0 mm|
|Neodymium||22 mm||-||43 mm||30 mm|
|AlNiCo||0 mm||43 mm||-||0 mm|
|Sheets and tapes||0 mm||30 mm||0 mm||-|
AestheticsFerrite magnets are not coated, they have an unattractive dark-gray colour and they stain under friction. Therefore, ferrite magnets are not suitable for use on clothing, e.g. as name tags. The surface is uneven and edges may have dents.
Neodymium magnets have an attractive silver colour thanks to the nickel-copper-nickel coating and they don't stain under normal use. Therefore, they are very suitable for decorations and gifts.
Danger for childrenStrong ferrite magnets are very large, which makes it harder for children to swallow them. Neodymium magnets of the same size have a much higher magnetisation, which can lead to serious complications when swallowed (see safety tips).
Danger for devicesMagnets can compromise electronic devices like pacemakers and hearing aids. Ferrite magnets are not as strong as neodymium magnets, which makes them safer to be near those devices. However, we still recommend a safe distance for both magnet types.
More information under What is the safe distance that I need to keep to my devices?