I’ll second this, I have a few Knipex hand tools, the oldest a set of slightly longer handled diagonal cutters like yours, the high leverage style with the thinner handle rubber. Worst I’ve done to them so far is nipping stainless screws. #8 and under by hand, but I have done 10-12 with a vise to add extra force. Probably a few hundred screws by now. Rusty, and ugly perhaps but just keep going. Still good on wire too. Most cheaper ones seem to wear out even on wire pretty quickly past the point of re-sharpening.
I’ll second this, I have a few Knipex hand tools, the oldest a set of slightly longer handled diagonal cutters like yours, the high leverage style with the thinner handle rubber. Worst I’ve done to them so far is nipping stainless screws. #8 and under by hand, but I have done 10-12 with a vise to add extra force. Probably a few hundred screws by now. Rusty, and ugly perhaps but just keep going. Still good on wire too. Most cheaper ones seem to wear out even on wire pretty quickly past the point of re-sharpening.