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This section describes information ranging from the principles of metal marking and processing to advantages grouped by laser wavelength.
It introduces marking examples and the optimal laser markers for a variety of materials such as aluminum, stainless steel, iron, copper, cemented carbide, and gold plating.

Main Marking Types

Black Annealed Marking

Defocused laser light irradiates below the surface of the material. This causes the carbon to heat up, turn black, and rise to the surface. This creates a smooth black mark on the surface of ferrous metals only.

The following materials anneal well

Steel / Carbide / Ferrous metals

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White Etch Marking

Laser light irradiates the target melting the surface and creating many small and highly reflective pools. These bright pools will appear white.

The following materials etch well

Steel / Aluminum / Carbide / Copper / Gold

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Laser light irradiates the surface etching away layers of the material. Repeated etches on the material will result in a deep engraving.This method allows users to engrave and mark with no coloration, similar to stamping. Engraved marking provides various benefits such as allowing for visibility to be secured even after painting upon marking completion.

Steel / Aluminum

The following materials engrave well

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Surface Peeling

Laser light irradiation peels off the surface layer leaving the base material visible.

The following materials peeling well

Surface peeling will work well on any painted or coated metal.

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Main Processing Types


Laser light irradiates a fixed point, usually with repetition to melt the material. The laser can easily melt through thin metals, fabrics, and leather. Because there is no contact, it does not cause a reaction with the item processed. Deformation and cracking is kept to a minimum. In addition, because it is possible to specify processing areas in extreme detail, it is possible to create localized holes or cuts in places where traditional cutting tools cannot fit.


Laser irradiation is used to heat solder paste that then joins metals. This irradiation is highly localized allowing for extremely precise soldering compared to traditional methods. This precision also reduces the head effected zone on the parts.

Solder Barrier

As a result of the trend of electronics getting smaller and thinner, connector terminals need to have solder barriers (nickel barriers) to stop the soldering from expanding. Conventionally, masking was used on locations where electroplating is not necessary, but removing the mask material took time and effort. Surface layer peeling using laser light is effective in these cases.


Laser welding irradiates two targets at the focal point and joins them together by melting and the soldifying the metal. It is possible to irradiate a pinpoint with high density energy and complete the process at high speeds. Material distortion due to heat is kept to a minimum. In the past, deformation occurred easily, but now even thin materials can be welded.

Absorption Rate for Metals

The graph on the left shows the different absorption rates of metal materials with a green laser (532 nm) and with the fundamental wavelength (1064 nm). There is no significant change to the absorption rate for iron (Fe), nickel (Ni) or aluminum (Al) when the wavelength is changed. However, the absorption rate for gold (Au) and copper (Cu) is affected greatly by changes in wavelength. The absorption rate for gold (Au) with wavelengths of 532 nm is approximately 30%, but with the fundamental wavelength of 1064 nm the absorption rate is less than 10%. Similarly, with a wavelength of 532 nm, copper (Cu) has an absorption rate of 40%, whereas that rate is less than 10% with the fundamental wavelength of 1064 nm.

Learn more about metal printing and processing. “What is the principle behind contrast marking?” “What is the absorption rate for each material?” Learn the ins and outs of laser marking with a focus on metal printing and processing. / Catalog Download


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