Probably not what your looking for, but the question was asked so I'm going to answer what I've done. Pretty much all of my motors are 3 phase. I got tired of replacing twist lock plugs on extension cords. People would pull on them and the cord ends would get loose. and the contacts would get warm and melt.

I've swapped most of my stuff over to pin and sleeve connectors commonly found in industrial settings.  They are color coded.  blue is 240v and red is 480v.  They come in 30 and 60 amp ratings and won't interchange.  They are overkill for most of what I do, but are extremely durable.  

Biggest downside is they are not cheap.  However, they can be found reasonable on ebay.  Here are some links for the 3 pin single phase outlets on ebay.  

60amp single phase 240v

30amp single phase 240v