What is the difference between 18 gauge and 22 gauge stainless steel?

The difference between 18 gauge and 22 gauge stainless steel is the thickness. The 18 gauge is 0.050" thick, and the 22 gauge is 0.031" thick. A link is provided below to an article with a list of the conversions. You'll note that the cited thickness for the gauges of stainless do not apply to galvanized steel, aluminum, zinc, brass or other metals.