There are multiple ways to mark parts and products. You can use hand stamps on smaller projects. This method is cheaper but slower and more labor intensive. If you need to mark a part with a sequence of dots, then a dot peen machine is a good idea. Then you have engraving machines that can cut grooves into hard surfaces, chemical etching machines that remove material, and laser marking machines that use a high-energy beam of laser radiation (fiber laser), to mark the surface of materials.