I wasn't referring to the shape of the drive. I figured it was 1/2-inch square drive. When I asked if it was a square (4-point) or double-square (8-point) socket, I was referring to the broaching of the service opening. The opening that engages the fastener. If it's a 12-point socket, that "S" doesn't denote "square." Perhaps it does have something to do with it being a special. I had a whole set of DOE wrenches with the same plain < W > / U.S.A. logo. They were all natural steel, with crude machining marks, characteristic of military grade.