> drive the nut by applying force to the flat of the nut
> and not to the corners as in a conventional design thus
I'm pretty convinced that these are wrenches with a pivoting part. I'm
not going to try to draw a picture: The main body of the wrench (the
part you hold with your hand) is a piece of bar stock, with an angled
end (say about 30 degrees from vertical) and a hole for a pivot pin.
The flat of the angled end is what actually hits the flat of the nut.
The pivot pin hole gets filled with a pivot pin, which also holds a
non-regular hexagonal frame. You slip this over the nut, it grasps
probably 2 flats. You then push on the handle, the handle pivots, the
flat of the angled end presses against a third flat, and the nut turns.
Automatic adjustment to within the limits of the swing of the handle
within the frame.
I've never used a set of these, but I've seen them advertised often.
They certainly look like they would work well on rounded-off heads.
Does this describe the 'magic spanners' you were talking about?
chris
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