The profile is not as pronounced as the schematic above, but the idea is the same; to exact pressure/torque on the flats of the nuts/fasteners rather than the corners. Therin lies my reference to Craftsman 6-pt sockets and their refinement to the present-day design. Not saying they were the first, but that's where I first noticed it. Makes sense for a lot of wrenches, etc.

John B.