non magnetizable magnetically attractable metal

ramonegumpert

Dear Gurus, :)

I am not sure what metal is suitable for the following kind of application:

1. this metal should allow a magnet to stick on to it via magnetism.
2. when the magnet is removed from this metal, it should not be magnetised in any way.
That is, after using it with a magnet over time it should not be magnetised.

I tested using a metal and a magnet. After using for some time, the metal became magnetised even when the magnet was removed. This metal held magnetism for some time before it loses the magnetism to a great extent if not completely.

I like to confirm that Iron core as used in an electromagnet has this property and can be used for this application.

Thanks.
Ramone

vk6kro

You have to use "soft" iron. This is iron with very little carbon in it.

This can be magnetized with a magnet or a current in a coil wound on it, but loses its magnetism when the magnet or current is removed.

The "keepers" that come with magnets are good quality soft iron if you just want to play with some.
I saw a reference that said wire coat hangers were soft iron.
Nails and bolts from a hardware store are likely to be steel and probably not suitable.

Yes, the iron core in an electromagnet would be perfect for this.

Bob S

Look at the B-H curve for 1010 steel in Fig. 2 on page 3 of
http://www.walkerscientific.com/Prod...4-Quadrant.pdf
I think the units are Gauss vs. amp-turns per meter.
Bob S

vk6kro

Yes, that looks OK. Very little remanent magnetism.

Also, school supply companies supply soft iron for school experiments.
Like this one:
http://sciencekit.com/soft-iron-rod/p/IG0024186/

$2.15 seems OK for a 200 mm piece of 6 mm soft iron.