A hand-operated tool lock mechanism secures a pair of grips in a closed locked state. The mechanism includes: a holding recess at the end of one grip; an engaging recess at the end of the other grip; a ring component removably and rotatably disposed in the holding recess, which engages with the engaging recess placing the grips in the closed state; and a catch for removably and rotatably inserting the ring component in the holding recess. The holding recess and the catch hold the ring component oriented away from the other grip when the ring component is disengaged from the engaging recess. When the hand-operated tool is used, the releasing of the ring component from the locked state causes the ring component to be held between the holding recess and the catch in an orientation in which the ring component does not contact the other grip.
