Maybe but it's got me interested ... the more I look at it, the more I realize that if the break happened due to unusual force, you'd think that the handle and pins would have gone first because the ends of that pliers are usually hardened steel. If there were a lot of force applied to the handles, it would have bent the handles or sheered the pins where the retractable handles pivot.

The only other thing I could think of it was that he was trying to cut heavy gauge wire that was way too big for this tool. The way the wire cutters are designed is the same as any other ... it's just to metal blades pressed next to one another. If you place a large wire in there that is too big and dense for the wire cutters, the blades will press down and because they can't cut into the wire, the blades start spreading out laterally. Pliers are meant to be strong with vertical force on the plier biting surface .. you can see it with all the solid metal around the base. But it isn't strong if the blades start moving laterally - here you can also see that there isn't as much metal to keep it from moving outwards.

So the more I look at it ... the more I'm guessing he was trying to cut heavy gauge wire ... or trying to use the wire cutter surface to cut something solid ... if that were the case, the plier mouth would have stopped moving towards each other and instead start spreading outwards .. which is a weak point and caused the break.

And you're right, if there was a subtle weakness or crack in the metal that corresponded with that kind of force, it would have been that much easier to break.

I love this sub ... dull men's club ... where I can waste time over analyzing a broken pair of pliers rather than doing the actual work I am supposed to be doing right now. Hope you are well.

That makes sense ... and since you've done it several times before, it probably weakened your pliers over time. Any time you bite into something with pliers and use the wire cutters and you have to use a bit more force than usual, you are pushing the two plier blades outward not towards each other.

That is why I was curious as to why they broke ... if you had tried gripping something with so much force that it broke one of the plier jaws - the jaw or the handle would have been bent out of shape first before the jaw would break .... (ask me how I know because I've done it before with a pair of vice grips)

But if you tried using the wire cutters and put force behind it while trying to cut something solid like a screw, then you are no longer pushing the plier jaws together, you are moving them laterally outwards ... and if you do that enough times, eventually the jaws will break .... (ask me how I know that because the more I analyze all this, the more I remember that I have broken pliers and wire cutters this way before)