Abstract: A frangible lock apparatus utilizes a pair of pan-shaped washers, each having shaft engaging tines. The shaft portion of a locking device, having the tumbler mechanism rotatably coupled to one end thereof, and the locking portion rotatably engaged the other, is provided with three pairs of notches along its length. Two pairs of such notches engage the pan-shaped washers located on opposite faces of the locking portion of the apparatus. The remaining pair of notches are disposed immediately adjacent the pan-shaped washer located closest to the tumbler end of the shaft. Upon pulling the tumblers, the shaft parts and the remaining portion thereof presents a virtually ungraspable nub and smooth shaped pan washer, accessible only through the small opening formerly used to house the tumbler mechanism.