Selective laser melting(SLM)/Direct Metal Laser Sintering (DMLS)

Print your SLM/DMLS parts with fast turnaround and wide variety of metal materials as fast as 4-5 days!

Overview: How SLM 3D Printing Works?

The Basics of SLM 3D Printing

Selective laser melting (SLM), also called Direct Metal Laser Melting (DMLM), is a type of metal additive manufacturing or 3D printing. Often, the terms SLM and Direct Metal Laser Sintering (DMLS) are used interchangeably. SLM Part Strength SLM parts are more robust and denser than investment cast metal parts, and they can help you get to market first with faster turnaround times.

3D printing basics

Benefits of SLM 3D Printing

3D printing benefits
  • SLM 3D Printing can provide a lightweight solution. Commonly advanced CAD techniques such as topology optimization and generative design are often used for this purpose, resulting in lighter parts (typically 25% to 50%) and higher stiffness. This is the key to high-end applications such as aerospace and other industries.

  • More complex structures can be formed efficiently. Therefore, some parts that cannot be de-moulded or cut by tools can be manufactured by SLM 3D Printing.

  • Designs can be made quickly with a minimum of material waste while maximizing strength.

  • Multiple, identical parts can be built on a single platform at one time, greatly increasing production efficiency.

Benefits of SLM 3D Printing With Unionfab

  • Unionfab can meet the production of all SLM materials (Stainless Steel, Aluminum Alloy, Maraging steel, Titanium Alloy, Nickel-base Alloy, Copper Alloy) in the market and has rich post-treatment processes (Polishing, Anodizing, Electroplating, Electroless plating, Heat Treatment, Painting, secondary machining, etc.).

  • Unionfab has four joint factories in South China and East China to cope with the changing market and social situation, with more than 200 imported and domestic printing equipment to meet various samples and batch orders.

  • we print SLM at a maximum size of 450mm and a minimum wall thickness of 0.3mm, meeting the printing accuracy of ±0.1mm, the secondary processing accuracy of ±0.01mm, and the sample order with the fastest delivery time of 3-4 days.

  • Conduct 100% full appearance inspection for all products and 2.5% critical dimension inspection for AQL. Provide standard inspection reports, support customers' online quality inspection before shipment, and control the production and inspection of products throughout the process.

  • Many experienced engineers with solid process capability can assist customers in pre-sales technical support of multi-process and undertake product-level services and orders.

Features of SLM 3D Printing


High complexity

Difficult to machine parts, custom medical pieces, hollowed or lightweight parts, and artistic pieces fall in this category.

Rapid or continuous revisions

Product development efforts and iterative designs are well-suited to SLM because there are no setup costs as in traditional manufacturing.


Internal Stresses

Because SLM is a higher temperature process, its printed parts often end up with internal stresses.


SLM machines are designed for high-volume industrial use, so they are expensive.

Design Guidelines: Selective laser melting (SLM)

  • Max Part Size
  • Layer Thickness
  • Minimum Wall Thickness
  • Tolerances
  • Post-Surface Treatment
  • Post Treatment
Max Size400 x 300 x 400(mm)400 x 300 x 400(mm)150 x 150 x 200(mm)
Min Size150 x 150 x 200(mm)150 x 150 x 200(mm)150 x 150 x 200(mm)

SLM Machines of Unionfab

Production Machines

ProcessNameNumbersProcess Size(mm)Detail
SLMBLT-S3008280*280*3502 files
BLT-S1503150*150*2001 files
BLT-S2006250*250*3000 files
BBLT-SLM15033150*150*2000 files
BLT-SLM28062280*280*3502 files

Post-Process Machines

ProcessNameNumbersProcess Size(mm)Detail
Sand-blastingSand blasting machine2400*800*5000 files
AnodizedAnodizing equipment2800*2000*5000 files
PolishChemical polishing line2600*1200*4000 files
Magnetic polishing machine260*60*600 files
PaintingPainting Line21000*2000*10000 files
ElectroplatingElectroplating line2600*1800*5000 files

Available Materials

Available Finishes

In addition to the removal of support structures, the part surface is media blasted to provide a uniform finish.
available finish - defaults

SLM 3D Printing Applications

Medical device
These metal technologies can be used to manufacture tooling, fixtures, motor parts such as rotors and impellers, cooling channels, etc. By using additive manufacturing you will get parts as resistant and efficient as with traditional manufacturing techniques.
Prostheses or Implants
DMLS and SLM technologies are also perfect for manufacturing prostheses or implants. As the patient’s individual anatomy is the key factor, customization of the part is a great benefit provided by DMLS technology. Meeting the patient’s specific anatomic needs reduces not only the length of time spent in hospital, but also the risk of problems normally caused by ill-fitting implants.
Tooling, Fixtures, Motor parts
The parts created with DMLS and SLM have mechanical properties equivalent to a cast metal part. These metal technologies can be used to manufacture tooling, fixtures, motor parts such as rotors and impellers, cooling channels, etc. By using additive manufacturing you will get parts as resistant and efficient as with traditional manufacturing techniques.

Industries with SLM 3D Printing

Consumer Products
Art and Fashion

Knowledge Base