A folding knife providing a safety lock mechanism that securely locks the blade in an open position. A bar spring in the handle is anchored at the rear handle end. Its opposite end is freely biased against the edge surfaces of the tang of a foldable blade. The bar spring includes a latch configuration complementary to a catch formed across the tang, which interfit when the blade is open. A transverse pushbutton serves to cam the free end of the bar spring from engagement with the blade when it is to be folded to a closed position.
