How Can You Weaken the Strength of a Standard Magnet?

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    Magnetic Strength
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Discussion Overview

The discussion revolves around methods to weaken the strength of a standard magnet, exploring various materials and techniques that could potentially alter the magnetic field. Participants discuss theoretical and practical approaches, including demagnetization, shielding, and the use of ferrous materials.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • Some participants propose demagnetization through successive hysteresis loops as a method to weaken a magnet.
  • Others suggest that applying a covering or shielding material could alter the magnetic field, but there is debate about whether this would make one pole weaker than the other.
  • One participant explains that using a high-mu material can concentrate the magnetic field, potentially distorting it but not necessarily weakening it.
  • Another participant argues that shielding one pole could create a path of low resistance for the magnetic field, making that pole appear weaker from a distance.
  • There is discussion about the effectiveness of different ferrous materials, such as soft iron, in dampening the magnetic field.
  • Some participants explore the idea of using thin metal plates or layers to reduce the field strength at one end of a magnet.
  • Questions are raised about the practicalities of implementing these methods and the materials required.
  • Participants discuss the potential for using wedge-shaped neodymium magnets that have varying field strengths at different ends.

Areas of Agreement / Disagreement

Participants express differing views on the effectiveness of various methods to weaken a magnet, and no consensus is reached regarding the best approach. The discussion remains unresolved with multiple competing ideas presented.

Contextual Notes

Limitations include the dependence on specific definitions of "weakening" a magnet, the effectiveness of materials discussed, and the practical challenges of implementing proposed solutions.

Who May Find This Useful

This discussion may be of interest to those exploring magnetism in physics, engineering applications involving magnets, or individuals seeking practical solutions for manipulating magnetic fields.

  • #31
So, with this iron/soft steel placing, I can just stick a piece of the metal on the end of it and it will make it weaker? Just like that? How much weaker? Would it affect the other side of the magnet? Would it affect other magnets that aren't touching the magnet with the metal attached?
 
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  • #32
Anything that will spread the field on one end will make the field stength weaker on that end. The opposite end will be slightly weakened by a plate on the end because it acts to partially short the field. Other magnets in proximity will also effect the field in an endcap.

How close are other magnets, and what are some of the disances involved?
 
  • #33
Endcap?

I think the other magnets will be about an inch away, maybe an inch and a half. But I could probably push it to 2 or maybe even 2.5 because of the fact that these are neodymium and very strong...
 
  • #34
Draven said:
Endcap?

I think the other magnets will be about an inch away, maybe an inch and a half. But I could probably push it to 2 or maybe even 2.5 because of the fact that these are neodymium and very strong...

OK What are the dimensions of the magnet would you intend to use?
 
  • #35
.25 x .25 x .5 inches.
 
  • #36
By end cap I meant the piece of iron.

This is all visual guess-work on what the fields lines would look like. I would find some annealed steel .125 thick. Or hot rolled stock. You probably don't have a mill or grinder so find some bar-stock 1/8 x 3/4 and cut 3/4 inch off the end. Cap one pole with this. Alternately you could find a large scrap transformer and use the core material stacked 1/8th inch thick. This might prove better, as you can add or subtract pieces to make it thicker or thinner.
 
  • #37
How much do you think it would take the weaken the field to 50% strength, for example? And what is the ratio between how much I weaken one pole to how much the other is therefore weakened somewhat (if that's even possible to know)?
 
  • #38
Draven said:
How much do you think it would take the weaken the field to 50% strength, for example? And what is the ratio between how much I weaken one pole to how much the other is therefore weakened somewhat (if that's even possible to know)?

That's what the dimensions I gave you were for. My guesstimate at what it would take to make one end half the field density, or field strength, of the other.

Come to think of it, given the distance of your other magnets, make it an inch square, and 1/8 thick.
 
  • #39
Well that is less than I thought. Thank you very much for answering all these questions. ^_^,
 
  • #40
Good luck.
 
  • #41
I took a hard drive apart and found a very strong magnet in it. Two pieces of metal material were sandwiched to it. I was able to slide one of the pieces of metal off of the magnet, I think the other was bonded to it with an adhesive of some kind. At any rate the open side of the magnet maintains a very strong attraction, the side with the metal bonded to it has a much weaker attraction quality although still existent. I also found that the poles were arranged in a manner I have not until this point experienced. After further experimentation I found the a similar effect, if I place a piece of wood between to magnets. The field is weekend or dampened.
 

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