Top Tips for Black Marking on Stainless Steel

Note: These tips are for a fibre marking laser.

We are often asked about what the best ways to mark stainless steel with text or graphics are.

Although these effects may look simple, there are in fact a few challenges to the process of getting more eye-pleasing and pronounced markings.

More often than not you will see muted, dull results. So how do you get markings that pop?

Fear not, the following tips are bound to impress.

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 quality.

With normal focusing, the peak power is very intense. This intensity 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.

To produce intense black effects, 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.

Light and sound of engraving

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

When you take the focus off the surface, the light on the metal starts to dim, and the sound becomes lower. When engraving stainless steel, the light on the metal is orange-red in colour, 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.

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

When trying to achieve a black mark on the metal, you need to find the perfect focal distance. It’s important to note the light and sound it generates while engraving.