Do magnets have a longer reach in a vacuum chamber?

[Sahaji]

Do magnets have a longer reach of attraction in a vacuum chamber?

 

[MisterX]

All else being equal, I don't think the attraction force would be significantly different in a vacuum than in air, because the magnetic permability of air is only slightly greater than the permability of a vacuum.

 

[NascentOxygen]

The permeability of the vacuum of free space is practically identical with that for air. So, no, the field around a magnet remains the same shape and strength.