Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Gillhk on 28/06/2018 10:37:25

Title: How to read the pull force of a magnet?
Post by: Gillhk on 28/06/2018 10:37:25

I have a chart and a graph for a ferrite magnet grade 5 / Y30, but I do not understand them and want to know what is the pull force of the magnet and how to read it on these 2 documents?

Title: Re: How to read the pull force of a magnet?
Post by: Colin2B on 28/06/2018 15:55:39

You can’t read pull strength from these charts, you will need to look at a specific magnet shape and size on a supplier website.
Y30 is a ferrite and won’t be very powerful eg 0.25 - 0.4kg could be less depending on configuration.

Title: Re: How to read the pull force of a magnet?
Post by: Bored chemist on 28/06/2018 19:16:43

I'm not certain, but I think (in this case) Kg is kilo Gauss rather than kilo grams.

Title: Re: How to read the pull force of a magnet?
Post by: Colin2B on 28/06/2018 23:05:48

Quote from: Bored chemist on 28/06/2018 19:16:43

I think (in this case) Kg is kilo Gauss rather than kilo grams.

Correct, Br is the remanence in milliTesla and kiloGauss

Title: Re: How to read the pull force of a magnet?
Post by: Gillhk on 29/06/2018 10:49:50

Most calculators seem to be for neodymium magnets but I have found an online ferrite magnet calculator to work out the pull force at adamsmagnetic website. (Not allowed to put the link)

The disc magnet is 20mm diameter x 3mm thick.

So I put:

OD outer diameter: 20 (although it didn't ask if it was mm)
Thickness: 3
Gap: 0
Material Ferrite
Grade Ceramic 5

Then I clicked calculate. The result was Fz 580.24 lbs

This can't be the correct pull force. What am I doing wrong? Or is there a better calculator I can use?

Title: Re: How to read the pull force of a magnet?
Post by: Colin2B on 29/06/2018 14:50:04

I think it is using inches. I put in 0.5 OD and 0.2 thick which is a C5 they sell and it returned 0.9lb which sounds reasonable.