Much depends on how you define "industrial". If you mean a simple metal
rackmount then http://www.gtweb.net/rackcase.html has some and there are
many more online vendors (hint: Google for "micro atx industrial case"). Of
course if you mean "hermetically sealed and capable of working in a hot
explosive atmosphere while being splashed by corrosive liquids", another
definition of industrial, you will have to search a bit harder.