Estimated reading time: mins

Metal 3D-printing with selective laser melting (SLM)

Play Video
What is Selective Laser Melting "SLM"? (3D Printing Technology) 05:07
SLM is a 3D printing process in which metal powder is fused by laser, creating a new object layer by layer. SLM stands for (Selective Laser Melting), which means that the laser selectively melts the metal powder only where the solid material is needed. In the end, the finished object can be removed from the powder bed.
Table of Contents

How Does Selective Laser Melting Work?

The process starts with a base plate. A scraper moves back and forth and spreads metal powder on
it. The laser then melts the powder only at the points where the object is to be made. At these
points, a solid metal part is created, while the loose powder remains. This process, known as
selective laser melting (SLM), is repeated layer by layer until the complete object is finished.

SLM Metal 3D printer laser is melting metal powder
Tomáš Vít / Youtube The laser melts the metal powder only where the part is to be created

The metal powder plays a central role in selective laser melting (SLM). To produce a part, not only
must the correct powder be used, but the base plate must also be made of the same metal as the
part itself. The part is built up layer by layer. Each layer is only 0.03 mm thin. This means it can take
up to 30 to 40 hours to produce a large part using SLM. During this time, the machine melts
countless layers of metal powder.

Base plate on which the metal 3D printed parts are made
Swann Rack / Holocreators Metal base plates on which the parts are created with metal 3D printing

Why Is a Supporting Structure Needed for 3D Metal Prints?

If the part to be printed has overhangs that cannot be supported by the powder inside the 3D
printer, then a supporting structure is required. As a rule of thumb, if the overhang is more than 45
degrees, a supporting structure must be added. This support structure holds the part during the 3D
printing process so that it does not sag or deform.

Metal 3D printed gas pedal with support structure
Swann Rack / Holocreators Metal 3D printed part with a support structure

After the printing process, the remaining metal powder and the supporting structures must be
removed. Parts made with 3D metal printing have a rough surface. Holes or threads cannot be
printed directly but must be drilled separately, such as with a CNC milling machine.

Metal 3D printed gas pedal without support structure
Swann Rack / Holocreators Finished metal 3D printed part without a support structure


Selective laser melting (SLM) is a metal 3D printing process. It can be used to create metal
components that are not possible with any other manufacturing process. In particular, complex
internal structures such as cooling channels can be integrated directly into the part. The costs for
metal 3D printing are very high compared to traditional manufacturing methods such as CNC milling.
For this reason, metal 3D printing has so far only been used in rapid prototyping or very small
production runs.

Do you want to 3D print a part in metal?

Holocreators offers professional 3D-scanning and reverse engineering services. We are also very
experienced with 3D printing, and we would happily advise you how to 3d print your part in metal. Please call us at +49 40 481133 or send an email

Swann has been enthusiastic about everything 3D for many years. His roots lie in analog holography, which brought him to digital 3D-modeling in 2011.

The rapid progress of various 3D-scanning techniques fascinated himso much thathe founded Holocreators together with his brother Miro Rack in 2015.

Ready to get started?
  • JPG, PDF, or PNG max 100 MB
    Drop files here or
    Accepted file types: jpg, png, pdf, jpeg.
You may be interested
Estimated reading
time: mins
With the help of specialized 3D scanners, you can 3D-scan people and animals. This allows you to create 3D models that can be 3D-printed or used for 3D animation. We'll show you three different devices that make such 3D scans possible.
Estimated reading
time: mins
Kitbashing is associated with model making. It is composed of the words "Kit" and "Bashing". “Kit” refers to "model kit". So, when a model maker is "kitbashing", he blends parts from different model kits. Similar to a collage. The model maker combines several individual models into an entirely new model.
Estimated reading
time: mins
A NURBS model consists of points connected by curves. A polygon mesh consists of thousands or millions of small triangles. CAD surface models are usually created using NURBS surfaces, while 3D scans are typically exported as a polygon mesh. The conversion from a polygon mesh to a NURBS model is called "reverse engineering".
Estimated reading
time: mins
Reverse engineering enables us to create a copy of an object. For this purpose, the part is 3Dscanned, then the 3D scan data is converted into a CAD format, and finally, the part is manufactured. All these steps result in noticeable deviations. If an error adds up over multiple steps, then we call this error propagation.

Thanks you!

Our representative will be in touch with you soon

Thanks you!

We are glad that you have subscribed to our newsletter