A lockset includes a lock cylinder, a lock casing, a first lock member, a second lock member and an anti-theft member. The lock cylinder includes a key hole and a first lock slot. The lock casing includes a second lock slot. The first lock member is accommodated in the first lock slot. The second lock member is accommodated in the second lock slot. The anti-theft member is sandwiched in between the first lock member and the second lock member. When two ends of the anti-theft member are respectively located in the first lock slot and the second lock slot, the lock cylinder and the lock casing are locked. When a contact surface between the anti-theft member and the first lock member or the second lock member is aligned with a rotation interface between the lock cylinder and the lock casing, the lock cylinder and the lock casing are unlocked.

A lock includes a lock casing having a lock cylinder hole, a pin replacing hole and a plurality of first pin holes; a lock cylinder rotatably arranged in the lock cylinder hole and formed with a plurality of second pin holes; a pin set including a plurality of first pins respectively accommodated in the first pin holes, and a plurality of second pins respectively accommodated in the second pin holes; an outer casing having an inner wall defining an accommodation space for accommodating the lock casing; and a pin plug including a main body having a first side abutting against the lock casing and a second side abutting against the inner wall, and a protruded block protruded from the first side for closing the pin replacing hole. The second side is opposite to the first side, and a shape of the second side corresponds to the inner wall.

A rekeyable lock cylinder with a cylinder body, an inner sleeve, and a plug assembly is provided. The plug assembly includes a plurality of key followers and a corresponding plurality of first racks and second racks disposed in carriers. The first racks correspond to operation of a user key and the second racks correspond to operation of a master key. As such, the lock cylinder is usable in a user/master key system. Disengaging either of the first or second racks from the key followers allows rekeying of the lock cylinder for the user key or the master key.

A method of forming lock cylinder plug using metal injection molding includes injecting a material that has a metal component and a plastic component into a mold. The metal component of the material is at least partially steel. The method includes molding the material into a lock cylinder plug having a key way passage. The method includes debinding the lock cylinder plug and supporting a portion of the lock cylinder plug using at least one ceramic support before increasing the density of the lock cylinder plug by performing a sintering heating process. The method includes inspecting the lock cylinder by inserting a key way portion of a key way gauge into the key way passage of the lock cylinder plug. Inspecting also includes classifying the lock cylinder plug as acceptable, at least in part, if the key way portion of the key way gauge is insertable entirely within the key way passage.

A rekeyable lock includes a lock casing formed with a lock cylinder hole, a pin replacing hole and a plurality of first pin holes; a lock cylinder rotatably arranged in the lock cylinder hole and formed with a plurality of second pin holes; a pin set including a plurality of first pins respectively accommodated in the first pin holes, and a plurality of second pins respectively accommodated in the second pin holes; and a pin cover arranged in the pin replacing hole and including a cover body formed with a groove, and a sliding block arranged in the groove and slidable relative to the cover body. When the sliding block is located at a predetermined position, the sliding block and the cover body are configured to respectively abut against an inner wall of the lock casing to fix the pin cover in the pin replacing hole.

An exemplary lock cylinder has an operating configuration and a rekey configuration, and generally includes a shell, a plug, and a rekey bar. The shell includes a body portion and a tower. The plug is mounted in the body portion for rotation between a home position and a rotated position, and includes a faceplate having an aperture. The rekey bar is mounted in the tower for movement between a first position and a second position. With the plug in the home position, the aperture is misaligned with the tower and the rekey bar is inaccessible. With the plug in the rotated position, the aperture is aligned with the tower and the rekey bar is accessible such that insertion of a tool through the aperture moves the rekey bar from the first position to the second position, thereby moving the lock cylinder from the operating configuration to the rekey configuration.