How To Make Laser Engraving Darker on Stainless Steel

Metal processing is something frequently asked of laser engraving and marking. If you’re in the laser engraving business, you’ll know that customers often request text or graphics on stainless steel. In the end, what catches their eye is the darkness of the laser engraving or the high-contrast black marking on the stainless steel. The more pronounced effects the marking produces, the more satisfied the customer becomes.

These effects may look simple enough, but there are some challenges to the process. These top tips will show you how to produce the black marking that customers are after. An S290LS fiber laser engraver was used for this article. A few little tricks will make customer satisfaction a piece of cake.
 

Tip 1. The out-of-focus laser engraving process

The focus distance is a crucial part of laser engraving. Before we fire up the laser, it is necessary to determine the exact distance between the laser and material to obtain the best processing quality.

With normal focusing, the peak power is very intense when engraving a piece of metal with a laser engraver. That intensity of laser will inevitably damage the surface of the metal and cause it to corrode. With a process like this, the workpiece usually turns brown after the processing. You can see this below.

The difference in laser engraving position between normal focal distance and out-of-focus modes

To produce the black effects we want, the out-of-focus technique is used to keep the focus away from the material, which reduces the peak power and keeps the laser from damaging the metal surface.

The difference in laser engraving position between normal focal distance and out-of-focus modes

Tip 2. Light and sound of engraving

The laser produces a very bright light when laser engraving metal at the normal focal distance, and the engraving itself sounds very sharp.

Laser engraving at normal focal distance vs. engraving out of focus

When you take the focus off the surface, the light on the metal starts to dim, and the sound becomes lower. When laser engraving stainless steel, the light on the metal is orange-red in color, and the sound is not that sharp.

Note: Put your safety glasses on when you observe the light, as the bright light can have long-term, harmful effects on the eyes.

Tip 3. Types of metal and surface treatment

There are many types of metal and surfaces treatments. The surface treatment varies as well depending on the type of metal. Different surface treatment leads to different darkness effects on the metal.

A few examples of common metal processing

Here are the hot tips for you. When trying to achieve a black mark on the metal, you need to find the perfect focal distance by lower the table with the control panel during the laser engraving. It’s important to note the light and sound it generates while laser engraving.

To discover more, you may refer to GCC LaserPro S290LS laser engraver's features and see its application with fiber.