Force solenoid - magnetite powdered tip

[kirikinny]

Hi

I am designing a solenoid to interact with a magnetite-powder tip. I can't find specifications about the magnetite I am using, and properties seem to depend on factors I don't know. Could you give me a rough estimate (just order of magnitude is fine) of the force give a certain magnetic field B of the solenoid and a tip of area pi*(0.2mm)^2 covered in magnetite powder?

Thank you
Cristina

 

[rigetFrog]

A uniform field won't exert a force on the solenoid.

It's the gradient of the field you need.

Assuming an air coil with ~ 100 Gauss and... I need the volume of the magnetic material, not just the area.

 

[kirikinny]

It says on the pack of magnetite powder: 'Particle size: 95% < 170 mesh (~53µ)'. We are going 'dip' the tip of the object, having area pi*(0.2mm)^2, into this magnetic powder.