Important knowledge of Neodymium Magnets.

[Ergo]

Repel vs Attraction:
I have found out that attractive mode is greatly stronger than repulsive mode. Look at this link.
http://www.magnetsales.com/Design/Calc_filles/PullAndPushBetween2RectMagnets.asp
Now there isn't any doubt any more whether the force of repelled magnets are stronger or weaker.

Demagnetizing myth:
The demagnetizing force of Neodymium magnets is approx 1400 KA/m which is far far greater than the force of
two neo magnets in repel mode. Therefore cannot two neodymium magnets in repel get demagnetized.

More info found at this site:
http://www.themagicroadshow.com/wizardmagnets/html/technical_info.html

A neodymium magnet will lose 1% of it?s magnetism every 10 years.

Neodymium magnets lose 0.12% of their magnetism per degree rise in temperature.
This is not a permanent loss. The magnet will recover it's magnetism on cooling.

Neodymium magnets must not be exposed to temperatures in excess of 80 degrees C because they
will not recover all the lost magnetism on cooling if the 80 degrees limit is crossed.
However, there are special grades of neos hat can handle up to 200 degrees C instead of just 80C.

Neodymium magnets get more powerful as they get colder!

The density of Neodymium magnets (weight) is 7.5 g / cm3.

Force example of Neodymium Magnet N42 at 25mm dia x 10mm:
Pull force in contact with mild steel is 16 kgs
Pull force generated by two magnets attracting each other is 54 kgs
Repulsion force generated by two magnets in repel is 33 kgs

By request:
Never let any neo magnets smash into each other from a distance and
don't let a magnet smash into solid iron. This will crack them into pieces.
Don't even let them attract together from a small distance. This will
shatter tiny pieces from the edge of the magnets and they become weaker.

Ones the protective seal on a neo magnet is broken moist can easily enter
the magnet and rapidly destroy it. Seal the broken area with thin epoxy.

[Iosh]

That's very interesting information, thank you Ergo!

I bought a lot of Neo's (20mm ? x 10mm N42 discs) a while ago to try and reproduce a little modified Wankel (will post if it works, don't worry!). Let's say I just can't separate two of them when joined together by hand, they are unbelievably strong but sadly are easily broken (got one smashed by letting them join from a distance) and that's a fact that should be stated too.

Cheers!

[Silvije]

Does anyone knows are they toxic or something... that little pieces goes averywhere...

[Gearhead]

Yes, they are toxic.

Details and interesting information;

http://www.lenntech.com/Periodic-chart-elements/Nd-en.htm

[Omega_0]

Well I didn't know that
May be in attracting mode each magnet enforces the field of the other and results in more force, while in repulsion the fields are weaken (each trying to reverse other's magnetism) and they repel with less force consequently.
Just guessing...

Now the real question is, how can is imbalance be used to gain some extra energy? Is it possible?