Abstract: There is described a metal workpiece generally having a surface and an identifier marked on said surface. The identifier has cells each having a corresponding cell size, including bright cells corresponding to a first binary value and dark cells corresponding to a second binary value different from the first binary value. The dark cells include a center portion being recessed relative to the surface thereby leaving a recess bounded by a peripheral wall in the corresponding dark cell, the recess having a depth of at least 100 microns and having an opening with a width ranging between 400 microns and 1750 microns and representing between 30 percent and 99 percent of the corresponding cell size such that the corresponding dark cell appears dark to an optical reader. The depth, the width and the cell size of the dark cells provide a shot blast resistance to the laser-marked identifier.

Abstract: There is described a metal workpiece generally having a surface and an identifier marked on said surface. The identifier has cells each having a corresponding cell size, including bright cells corresponding to a first binary value and dark cells corresponding to a second binary value different from the first binary value. The dark cells include a center portion being recessed relative to the surface thereby leaving a recess bounded by a peripheral wall in the corresponding dark cell, the recess having a depth of at least 100 microns and having an opening with a width ranging between 400 microns and 1750 microns and representing between 30 percent and 99 percent of the corresponding cell size such that the corresponding dark cell appears dark to an optical reader. The depth, the width and the cell size of the dark cells provide a shot blast resistance to the laser-marked identifier.