Either way, it's odd, because it seems unnecessary.
Couple other observations...
- No accessories. All my sets with male drive tangs have an extension and/or a knuckle joint, maybe an L handle.
- All my sets with male drive tangs that are forged and/or machined (Eastern Machine Screw, Spezial Werkzeuge Fabrik) are hex drive, except Herbrand, which is square, akin to early Plomb. All my other sets with square male drive tangs (CM&D, Syracuse, Charles Miller) are malleable iron.
- All the sockets in my male drive tang sets have 6-point openings. Double-square is bizarre. If it was automotive, that relegates it to plugs.
@Patrick Eubanks What is the drive size? Is it 1/2-inch? Or something odd?