A lock mechanism for a wooden box, consisting of a lock plate and two spring plates. The lock plate is lightly curved in profile and has a long rectangular terminal, which is separated from the main area of the plate by a transverse roll moulding. The plate widens toward the other end and has a rectangular slit at its centre. Rivets set to either side of the slit fasten the springs underneath the plate. The plate widens to a point just beyond the slit and then tapers to another narrow rectangular projection, with a transverse perpendicular bar set close to its end.