Sto og hang. If you were somewhere with friends, standing around and waited for nothing in particular to happen, or not happen. Just watching people going by and chat with your friends. It comes without a timer, but it's likely to be at least 15 minutes and counting. You need to actually be on your feet during this "exercise".
I'll probably over-explain it again, but if your workers sto og hang they were taking a break when they were not up for one, or they had run out of assignments and were idling even though there were other things waiting to be done.
Actually, I just found my gigantic dictionary lists all three "hanging about/around/out", under the Norwegian headword "henge omkring" (to be clear). Loitering ("stand or wait around without apparent purpose"), is an even better translation.
(There are some notes about use in BrE and AmE that would explaing why one or the other sounds weird.)
"Loiter" in English has a negative connotation that "hang out" does not, but "hang around" and "hang about" do, implying idleness, uselessness, or unwanted presence. "Hang out" in this sense is anyway an American usage originally, as the OED makes clear (text search for the intransitive senses):
Here we have an older British usage meaning to reside; and an American usage meaning to associate casually with friends. It is possible that at one point "hang out"="loiter" in connotation, as a New Yorker citation from the 1940s suggests, but it no longer does, in my opinion.
(You will need to copy and paste to get the whole link above; it expires in 3 days.)
In (British) English, "hanging about/around" definitely has negative connotations, like "loitering", and would be used in the context of someone (usually) standing in the same place without good reason, and with potentially nefarious motivations. (Somehow people just waiting for lifts look more purposeful!)
In contrast, "hanging out" is a more legitimate way to spend time, specifically relaxing. Commonly, you'd hang out with other people (my daughter's friend comes over to "hang out" at our place); but not necessarily (I might go to the coffee shop on my own, to just hang out there). To spend time relaxing.
Oddly, I think if you are hanging out at home, you have to be with someone else (i.e. a guest), but if you're somewhere else, you can be on your own.
Well, in Norwegian henge is both something young people do with their friends (the main activity is being with their friends, this meaning is the newest one and obviously derived from the English use of hanging out) and something you do together with your friends when you don't have anything specific on your mind, just hanging around (about?) the mall or outside the fast food store. One individual can do it alone, but more often than not that's because he's up to no good (by housewife standards). Stå og henge is the kind were you are just standing somewhere (in a group) more or less without any other purpose than just that. If you are going to meet some friends (hang out) skip the standing part of the Norwegian phrase. My baby sister would answer mom Vi skal bare henge in response to were she was going with her friend.
(I'm writing this from my mobile so I hope it didn't get to messy an explanation)