Shearable lock assembly and method of manufacture

A lock and a method for manufacturing the lock. The lock comprises a shell having an interior cavity, a plug received in the interior cavity rotatably and axially slidably therein and defining a keyway configured to receive a preselected key, and a tumbler insertable in the plug. The tumbler has a plug portion disposed at a first axial location within the plug and resiliently biased outwardly toward a locked radial position and associated with the keyway such that said preselected key inserted in the keyway locates the tumbler in an unlock position and a shell portion disposed at a second axial location in the shell wherein the second axial location is axially spaced from the first axial location. The shell, the plug and the tumblers are configured such that the tumblers are sheared between the plug and the shell when the plug and the shell are forced axially toward each other.