Those sockets are usually for panel mounting....I think the Wiremold outlet strip raceways use those.
Is it code-approved to integrate one of those outlets strips into a frame - bolting it on?
I've seen free-standing equipment racks for computers with one of those strips going up one corner. It is then terminated using a 14 or 12-gauge SJT cord.
The one I saw used an L5-15 cord cap so it wouldn't get kicked out of the socket(the rack held computer server or router equipment here at work.)
Look at this pdf file....scroll down, it's around page three. http://www.wiremold.com/shared_content/pdf/ED795.pdf