What kind of metal is it, and how is it being used? If it is a stationary piece of nonferromagnetic metal with no current flowing, then the magnetic field is not going to be much different than the normal ambient field, which is about 0.5 Gauss (0.00005 Tesla).
If it is ferromagnetic, moving or has current flowing, then the field may be different, but we would need more detail to answer any further.