Presented in this article surface-mounted lock is a replica of XIX century lock. The mechanism of lock is typical for Russian surface-mounted locks XVIII - XIX centuries. The system of levers allows to adjust in wide range pressure on the key during manufacturing of lock as well as it allows use rather thick springs, which in turn significantly simplifies manufacture of springs. Mechanism of lock if properly adjusted works very softly, reliable in use,can be adjusted within a wide range, parts of lock do not needs high accuracy . Even at present, in Russia sometimes we can meet similar locks made in XVII-XIX centuries in use, mainly on the doors of churches.
Spring of represented lock made from mild steel, carburized, and then heat treated.