Shaw Paf

[NightWinder]

It not sand cast?

It should be a sand casted magnet with the two pole edges ground smooth, and the ends are still pebbly looking.

They are cast....They have been tumbled, I'm tellin' ya!!

[David Schwab]

They are cast....They have been tumbled, I'm tellin' ya!!

Same magnet. I guess they do look tumbled. Or the sand casting can't do a sharp edge.

[PoorMan]

I finally found a place that would do unoriented A5.

And the supplier is?

Would you consider selling a couple to a hobbiest?

[JGundry]

And the supplier is?

Would you consider selling a couple to a hobbiest?

Oh boy. Not sure yet if I want to give away the supplier. In reality it is a piece of cake for any magnet maker to do unoriented A5 but very few will do it. I have not even placed an order yet. The magnets I got yesterday were sample magnets from the manufacturer.

[PoorMan]

Oh boy. Not sure yet if I want to give away the supplier. In reality it is a piece of cake for any magnet maker to do unoriented A5 but very few will do it. I have not even placed an order yet. The magnets I got yesterday were sample magnets from the manufacturer.

Fair enough. If you decide to share or are willing to sell a couple please PM me.

Thanks,
Dave

[belwar]

Can someone fill me in as to what exactly "un-ortiented" means? Even a brief description helps.

[JGundry]

Can someone fill me in as to what exactly "un-ortiented" means? Even a brief description helps.

Oriented Alnico has the magnetic grains oriented in the direction of the poles for the magnet. So for a humbucker bar they would be oriented perpendicular to the pole faces on the long thin edge of the bar. This is done by exposing the magnets to a magnetic field for some part of the casting process to set the orientation. I don't know exactly when or how long but I believe it is done for a period of hours until the magnets have cooled sufficiently. Unoriented Alnico is not exposed to a magnetic filed during casting so as a result the magnetic grains are randomly oriented. A2 is unoriented. In terms of how they sound, in general terms I would say that oriented Alnico has a more focused sound when a note is picked and unoriented has a crunchier, sort of splashy sound when a note is picked.

I probably messed some part of this description up in terminology or process but I think more or less I'm in the ball park with the explanation.

[Joe Gwinn]

Oriented Alnico has the magnetic grains oriented in the direction of the poles for the magnet. So for a humbucker bar they would be oriented perpendicular to the pole faces on the long thin edge of the bar. This is done by exposing the magnets to a magnetic field for some part of the casting process to set the orientation. I don't know exactly when or how long but I believe it is done for a period of hours until the magnets have cooled sufficiently. Unoriented Alnico is not exposed to a magnetic filed during casting so as a result the magnetic grains are randomly oriented. A2 is unoriented.

Orientation results when the alnico alloy solidifies (freezes from molten) in the presence of a strong magnetic field, thus ensuring that all magnetic domains are aligned along that field. If no external orienting field, those domains end up pointing every which way.

Oriented materials must be magnetized in the direction of the original orienting field, or exactly opposite to that field. Unoriented materials don't care, but are weaker in all directions than oriented materials are in their preferred direction.

If one is planning to magnetize a bar magnet through one of its short dimensions, then either the bar has to have been cut from the oriented ingot such the the orientation is along this short dimension, or one must use unoriented alnico.