Abstract: A safety lock-set is provided which includes a main body, a socket and a bushing. The heat-treated socket is used not only to close off the lock-pin hole of the main body, but also to form a skirt for the spring and the back end of the latch. The heat-treated bushing is provided to sleeve over the connecting area of the set bar and the latch from the lock barrel side. The socket and the bushing connect together with a respective curved notch on each one, to form a closed connecting sleeve to protect the connecting areas of the latch and the spring and the set bar, in order to prevent someone from drilling through the lock-set.