Laser Etching vs. Laser Engraving: Which Should You Choose?

If you are relatively new to laser technology, you may be wondering what the difference is between laser engraving and laser etching. More importantly, which one is right for you.

The main difference between laser etching and laser engraving is that etching melts the micro-surface to create a raised mark, while engraving removes material to create a deeper mark. Both processes use high temperatures to create a permanent mark on the metal surface.

Both processes are heavily used for part traceability. Let's take a deeper look at each process to see which is best suited for which application.

Laser Etching Process

When etching, the laser heats and distorts the microscopic surface of the material. By doing so, the laser-etched surface expands and creates a texture.

Laser etching produces a black and white mark and is the most effective process for permanently marking most types of materials. Etching is faster than engraving because it requires less laser beam energy.

You may need laser etching if:

Parts are made of any metal except stainless steel

The fastest laser process

A cost-effective laser that requires less laser power

Integrate laser marking before non-abrasive processes, including powder coating, e-coating, and heat treating

Laser Engraving Process

With the engraving method, the laser evaporates a thin layer of material to create the tracking code. This is done by sending highly localized laser pulses to your part.

Instead of creating a micro surface above the material, laser engraving penetrates deep into the material. Engraving depths can reach up to 500 microns.

You may need laser engraving if:

The part is made of steel or aluminum;

A mark with maximum durability;

Integrated laser marking prior to abrasive processing (including sandblasting and grit blasting).

In the following video, the black mark is created by deep laser engraving and the white background is created by etching.

Why do you need laser etching and laser engraving?

If you鈥檝e used dot peening, inkjet printing, or printed labels to track parts in the past, you know that these marking technologies come with significant maintenance and consumables costs. In addition, you may have had to deal with inconsistent results due to unreliable marking systems.

How Etching and Engraving Solve These Problems

Laser direct part marking encodes information that cannot be separated from the product throughout its life.

Laser marking has high resolution; a lot of information can be packed into a small area (especially if you are using a  Data Matrix code).

Laser etching and laser engraving machines require very low maintenance.

Fiber and CO2 laser systems require no consumables.

Pulsed fiber lasers have very low power consumption.

What industries use laser etching and engraving?

Many of our customers use laser etching and engraving to collect a wealth of information for their traceability programs. Some of them also use this information to optimize their manufacturing processes.

They use these laser processes to mark all types of barcodes, including QR and Data Matrix codes, as well as serial numbers and alphanumeric characters. Others also choose to brand their products by marking their company logo on parts.

Here are the most common industrial applications

Automotive Industry

Automotive manufacturers have long required traceability from their suppliers. They were early adopters of Data Matrix codes as a way to uniquely identify parts that go into final assembly. Parts are scanned at key steps throughout the value chain to ensure compliance and enforce accountability. Today, they are demanding part identification earlier.

Primary Metal Industries

Smelters, die casters, hot and cold mills, and extruders came late to the game, largely because of demands placed on them by their automotive customers. They are finding that the data they collect from their internal traceability programs helps them optimize their processes. Others are using laser marking to differentiate themselves from competitors by making products that meet strict environmental standards.

Medical Device Manufacturers

The FDA has set strict regulations requiring the identification of medical devices. It requires most medical devices to be identified using unique identifiers.

Other Industrial Laser Marking Processes

Laser etching and laser engraving are not the only processes used in industrial applications. Although less common, laser annealing is the only solution for marking stainless steel and chrome-plated workpieces.

The reason is simple: it is the only process that produces a permanent mark while maintaining the part鈥檚 natural corrosion resistance.

Laser annealing heats the metal rather than engraving it. This process creates a black mark beneath the surface through a reaction called oxidation.

The difference between annealing and etching is that annealing is a chemical reaction and does not melt the surface of the material. The difference is subtle.