Is laser marking permanent?

Yes, laser marking is permanent.
Laser mark ing technology, is the use of high energy density laser beam local irradiation of the material surface. This causes the surface material to evaporate or undergo a color change, thus leaving a permanent mark.
This marking will not disappear or blur due to environmental factors (e.g. high or low temperatures, acid or alkali corrosion), daily wear and tear, or the passage of time. Unless the material itself is physically removed (e.g. by grinding or cutting).
This characteristic of laser marking makes it widely used in industrial manufacturing, anti-counterfeit marking, jewelry, electronic parts, automotive parts and other industries.