As you may know, one of the most popular ways to permanently mark different types of metal is by using lasers. But what you may not realize is that there are actually many ways that laser beams can permanently mark metals – and each one of them is unique.

If you’re thinking about marking metals using a laser, you need to understand each of these methods and what makes them different.

Laser Marking

Laser marking is a process that uses a laser beam to alter the surface of a material and permanently leave a mark on it. The laser that it uses is low-powered, and the beam is slowly moved across the surface to create a high contrast mark using annealing, coloration, or carbon migration.

Unlike other methods, laser marking does not remove any material and leaves the surface of the material intact. Because of that it is often used to mark medical equipment that may be placed inside the human body. It is also very precise, and often used to add bar codes, logos, text, and serial numbers to metal products.

Laser Engraving

In contrast to laser marking, laser engraving actually removes part of the surface of the metal to create a cavity that leaves a permanent mark. It uses a high-powered laser beam to literally vaporize the material, and sometimes goes through several passes to increase the depth of the cavity – up to 0.02 inches on metals.

The main advantage of laser engraving is that it is durable and perfect for items that are expected to go through high wear – or materials slated for abrasive treatments. It is also a fast and relatively cost-efficient process, which is why many industries choose to use it.

However because laser engraving will remove part of the metal, it can compromise its structure. As such it is generally not used for any safety-critical parts.

Laser Etching

Strictly speaking, laser etching is a type of laser engraving. The difference between them is that instead of vaporizing the material, laser etching uses a high-powered laser to melt the surface of the material and create a very shallow mark. Typically the depth of laser etching is no more than 0.001 inches.

While laser etching is as fast and cost-efficient as laser engraving, it is not as durable – because of its much shallower depth. That makes it unsuitable for items that will go through high wear, and susceptible to being obstructed by dirt or paint.

At the same time because etching is shallower, it can be used on more varied material thicknesses.

Which to Choose?

Now that you know the difference between laser marking, laser engraving and laser etching – it should be much easier for you to decide which one you need. It really boils down to the reason why you want to permanently mark a metal material, as well as other factors such as the type of material, what it will be used for, and what mark needs to be made.

In general if you want to leave a precise mark without affecting or damaging the material then laser marking is the way to go. On the other hand if you want to leave a very durable mark then laser engraving is best, whereas laser etching is ideal if the item isn’t going to face much wear.

If you still aren’t sure which one to use you may want to consult an expert and ask for their advice. At the same time you may also want to get quotes for the cost of each option and the duration it will take.