I've EDCed one for a year now. I've wedged it in between two frozen together items and put the boot to it. It isn't bent yet. :P I would say that it is as strong as a good knife blade, maybe more.

The wrench is a little funny at first, becuase it only grips in one direction. One side is smooth, the other has teeth, which you could (I suppose) catch on the corners of the bolt, or on the flat. If you catch on the corners, you could round the item, but on the flat, no chance.
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-IronRaven

When a man dare not speak without malice for fear of giving insult, that is when truth starts to die. Truth is the truest freedom.