SLS vs. DMLS: Key Differences & Performance Comparison

AttributeSLSDMLS

Attribute

Typical layer height

SLS

100–120 microns

DMLS

30–40 microns

Attribute

Typical tolerance standards

SLS

± 0.015” or ± 0.002" per inch — whichever is greater*

DMLS

+/- 0.005” for the first inch, plus +/- 0.002” for every inch that comes after

Attribute

Typical build volume

SLS

330 x 330 x 580 mm

DMLS

250 x 250 x 250 mm

Attribute

Minimum recommended feature size

SLS

1 mm

DMLS

0.5 mm

Attribute

Parts need support structures

SLS

DMLS

Yes

Attribute

Has isotropic material properties

SLS

Yes

DMLS

Yes

Attribute

Material types

SLS

Thermoplastics like polyamides and nylons, metal, ceramic, and glass

DMLS

Metals and alloys such as aluminum, copper, and stainless steel

Attribute

Print volume

SLS

Can print builds around 2 feet in length

DMLS

Smaller builds, around a 10-inch cube in size

Attribute

Can print in metal

SLS

DMLS

Yes

Attribute

Advantages

SLS

Cheaper for prototyping and testing out product forms
Parts don’t need supports for printing
Can be dyed different colors and vapor smoothed
Larger build volumes than DMLS printers
Can make more parts at once

DMLS

Can create high-strength parts with many different types of metals
Parts are super durable and have great chemical, mechanical, and thermal properties compared to SLS
Parts usually have better resolution than SLS parts

Attribute

Disadvantages

SLS

Limited to only working with plastics
Not as great of mechanical properties as DMLS parts
Parts are more prone to shrinking and warping

DMLS

DMLS tends to be more expensive because of its high material costs
DMLS prints need support structures during the build process
They have smaller build volumes
They also print smaller quantities than SLS machines

* The tolerances we’ve listed for SLS are when working with nylon 12 material, but tolerances will differ depending on what material you choose for printing.

DMLS and SLS have similar resolution and minimum feature size. However, DMLS can print in metal and the powder is more recyclable. SLS parts do not need any support structures, unlike DMLS parts.

SLS vs. DMLS: Technology Comparison

Fundamentally SLS and DMLS share the same technology, i.e., powder bed fusion. The difference lies in the power of the laser and the fact that DMLS machines need to have their build volumes filled with an inert gas during printing.

SLS vs. DMLS: Material Comparison

SLS can print in a variety of polyamides including: Nylon 12 and elastomeric materials like TPU (Thermoplastic Polyurethane). DMLS is primarily a metal printing technology that can print in stainless steel, titanium, aluminum, nickel alloys, and some precious metals. DMLS is also able to print in nylon.

SLS vs. DMLS: Product Applications Comparison

SLS is primarily used for products that don’t need to be used in high-load and high-temperature environments. SLS parts are also used for functional and visual prototypes. DMLS, however, is better suited to printing high-performance products and components that are exposed to extreme environments like those found in the aerospace and automotive industries.

SLS vs. DMLS: Print Volume Comparison

SLS and DMLS have comparable build volumes, with SLS machines having slightly larger volumes than more high-end machines. DMLS parts become significantly more expensive as their size increases.

SLS vs. DMLS: Surface Finish Comparison

Due to the nature of the sintering process, both technologies will produce parts that have a rough/matte surface finish. Both technologies can have their parts post-processed to improve surface quality. Typical processes can include: tumbling, bead blasting, and polishing; whereas only polishing is possible on DMLS metal parts.

SLS vs. DMLS: Cost Comparison

SLS is significantly cheaper than DMLS. This is due to the high cost of the metal powder, high energy consumption, as well as the more expensive machines used for DMLS printing.

What are the Mutual Alternatives to SLS and DMLS?

While SLS and DMLS have their fair share of perks, there are a couple of alternative printing options you can consider depending on the project you have in mind.

Multi-jet fusion (MJF): This is also a type of powder-bed fusion process (and one that we offer, too). MJF is a good alternative for SLS because it works with similar polyamide materials but uses a printer head that deposits the materials more like an inkjet printer as opposed to the laser that SLS uses.
Metal binder jetting: We also offer metal binder jetting, which also involves working with metal like DMLS. It also uses a print head to lay out a binding agent that fuses metal layers together, and then it’s left to cure and later sintered or infiltrated with bronze. It’s much cheaper than DMLS but has a higher chance of shrinkage and more pores (and often not as fine of features).

What are the Other Comparisons for SLS Besides DMLS?

Other comparison technologies for SLS include:

SLS vs. MJF: Multi Jet Fusion is a suitable alternative to SLS. It can print with similar resolution and materials. MJF also has improved mechanical properties. To learn more, see our guide on SLS vs. MJF.
SLS vs. Binder Jetting: Binder jetting is functionally similar to MJF. But, instead of a laser fusing the powder, a binding agent is applied with an inkjet-type printing head to fuse the particles. Post-curing is required to create strong parts.

What are the Other Comparisons for DMLS Besides SLS?

Other comparison technologies for DMLS include:

DMLS vs. EBM: Electron Beam Melting is also a powder bed fusion technology. But, instead of using a laser, an electron beam is used to melt the metal powder into a final part. This produces parts that have homogenous mechanical properties. To learn more, see our full guide on DMLS vs. EBM.
DMLS vs. DED: Directed-energy Deposition is a metal printing technology that feeds a metal wire to a printing nozzle. The metal is then melted at the nozzle and deposited on the build plate layer by layer, similar to FDM printing. This produces parts that have homogenous mechanical properties.

Kat de Naoum

Kat de Naoum is a writer, author, editor, and content specialist from the UK with 20+ years of writing experience. Kat has experience writing for a variety of manufacturing and technical organizations and loves the world of engineering. Alongside writing, Kat was a paralegal for almost 10 years, seven of which were in ship finance. She has written for many publications, both print and online. Kat has a BA in English literature and philosophy, and an MA in creative writing from Kingston University.