Magnetic Field Specification of Magnets

[nickypoo]

I'm not sure where else to post this.

How are magnets specified? If a magnet is "0.2" Tesla, is that the maximum magnetic field present at the surface?

 

[Simon Bridge]

Magnets are specified however the manufacturer or retailer wants to.
A lot will depend on the intended use of the magnet.

Often, a tesla-rating for a permanent magnet is the strength of the magnetic field measured at or very close to the center of the pole surface ... or averaged over the surface.

You usually only want them as a rule-of-thumb for comparing magnets.
Manufacturers will usually supply information about what the various specifications mean.