We have surveyed, designed and installed wireless networks in many industrial environments that includes metal fabrication plants with great success. Overall the Cisco Aironet hardware has shown great performance and adaptability in the almost eight years we've been installing it and I think you will find this to be true once it is properly placed at your facility.
There are some issues to be aware of such as higher instances of multipath mitigation or possible sources of EMI from the machinery, these are discovered during the course of a thorough site survey and then adapted to with various equipment configurations in both hardware and menu configs.
