Ahhh, Chas... anyway, I've had the same half inch drive Craftsman HD ratchet wrench now for over 35 years and, during that time (but not in the last couple of decades) I can vividly recall
bouncing on the end of a pipe that was over the handle, in order to break a nut loose. Let's see, I was probably about 180, plus bouncing... yeah I think that gets in to the three hundred ft/lbs range. Soooooooo, I'm thinking that wrench is good for 400 ft/lbs or more.