Abstract: An assembled lock cylinder comprises a cylindrical core having a cylindrical outer surface and an end face and defining at least one through hole through the wall of the cylindrical core; a connecting plug having a cylindrical portion inserted into the cylindrical core through the end face and defining at least one pin hole extending inwards from the surface of the cylindrical portion; and at least one pin. The connecting plug has at least one protrusion extended outwards from the outer surface thereof that is inserted into the cylindrical core. The cylindrical core has at least one receiving recess sized to receive the protrusion. When the connecting plug engages the cylindrical core the through hole aligns with the pin hole and the pin can be exactly mounted into the through hole and the pin hole, so the connecting plug cannot move axially and circumferentially with respect to the cylindrical core.

Abstract: The present invention provides a padlock that comprises a shackle, a lock body, a lock cylinder assembly disposed at the middle portion in the lock body, and a combination lock assembly. The padlock of the invention can be operated by either the key or the cipher. The invention also provides a padlock having an interchangeable lock cylinder assembly.