What types of material can be welded with MIG machines?

What types of material can be welded with MIG machines?

Typically, less amperage is required to weld thinner material and more amperage is required to weld thicker material.
A general rule-of-thumb is, one ampere for every .001″ of metal thickness. For example, 10 gauge (or 1/8″) material equates to 125 amps.