STEM means "science, technology, engineering and math". And, in fact, is almost always about a
degree in the aforementioned areas as it was coined by the NSF in 2001.
You can fool yourself and try to appropriate the acronym STEM for whatever definition you please in service of whatever goal you wish; however, the US government is quite clear as to what a STEM job or degree is. I guarantee that welders, woodworkers, etc. will not be granted a STEM visa to the US.
