Fathom is hiring! For all open positions, visit our Career Center.

DMLM vs. DMLS – Is There Really Any Difference?

This article is intended to clarify an aspect of metal 3D printing terminology that is commonly misunderstood and often used incorrectly.


DMLS = DMLM is basis for this statement, so here is a simple analogy.

Visualize a bucket of ice cubes on your conference table.

If left to sit for a short while at room temperature, the individual cubes will soon start to melt. After putting the bucket of ice cubes back in the freezer, the ice will stick to each other, such that if you try to pull out one cube you will most likely get a random glob of multiple cubes stuck together. This fusing of cubes together is analogous to the most common interpretation or use of the word ‘sintering.’ Note that the properties of the glob of cubes may or may not resemble the properties of an individual cube as there will likely be pockets of air, or different density ice, interspersed within the mass of ice.

If you left this same bucket of ice cubes out on the table long enough for all the cubes to melt, you would have a bucket of water. If you put that bucket of water back in the freezer it would solidify into effectively one large homogenous and fully dense piece of ice.  This is analogous to what happens in DMLM and DMLS 3D printing with metals.

The laser provides enough heat (energy) to melt the metal particles. The laser is directed at those particles and then, as the laser moves on, the melt pool rapidly solidifies into a fully dense homogenous structure. In this case, the properties of this new block of ice exactly resemble the properties of the individual ice cubes we started with and do not have air, or different density, interspersed within the mass.

Simply put, sintering is not melting.

Sintering Does Have Its Place

During traditional sintering of powder metal all kinds of processes were developed to address the porosity or fill the interstitial spaces between particles – like infiltration and hipping. These processes are not needed with DMLS or DMLM as the resultant structure is fully-dense as produced.

If you actually needed a portion of a part to be sintered within a DMLM part, let’s say the center, it is possible to change the power of the laser for that defined area of the part. Then the laser can be turned back up to complete the rest of the part, resulting in a part with a less dense/solid center.

EOS Technology

When using EOS default parameters for DMLS, a melt pool is formed and a fully-dense structure, equivalent to wrought, results. This is identical to the process referred to as DMLM.

EOS prefers the word ‘solidification’ (as opposed to ‘sintering’) be used in describing their DMLS (Direct Metal Laser Solidification) process

There are sintered-based 3D printing technologies as well, but EOS is not one of them – EOS is melt-pool based. A 3D printed part is heated in an oven to harden it and reduce its porosity.

The expert metal 3D printing technicians at Fathom can help you successfully incorporate metal 3D printing into your next prototyping, manufacturing or product design project.

Talk with a Fathom expert directly about advantages of DMLM and DMLS.

Manufacturing Locations Across National Time Zones
The Fathom Advanced Manufacturing Platform

ISO 9001:2015 Certified + AS9100 Rev. D Certified + ITAR Registered
+ NIST 800-171 Compliant + ISO 13485 Certified


1050 Walnut Ridge Drive
Hartland, WI 53029
AS9100 Rev. D Certified

620 3rd Street
Oakland, CA 94607
ISO9001:2015 Design Certified

444 W. 21st St. Ste. 101
Tempe, AZ 85282

7770 Washington St.
Denver, CO 80229
ISO9001:2015 Certified

14000 N.W 58th Court
Hialeah, FL 33014
ISO 9001:2000 and ISO 13485 Certified

1207 Adams Drive
McHenry, IL 60051

401 W. Shore Blvd.
Newark, NY 14513
AS9100 Rev. D Certified and
ISO9001:2015 Certified

1920 Slaterville Rd
Ithaca, NY 13073

1401 Brummel Ave
Elk Grove, IL 60007

13758 Johnson Street NE
Ham Lake, MN 55304

6415 Angola Road
Holland, OH 43528

1050 Walnut Ridge Drive Hartland, WI 53029
AS9100 Rev. D Certified

1801 Rowe Lane
Pflugerville, TX 78660
ISO AS9100, AS9100:2016 and AS 9001:2015 Certified

1513 Sam Bass Rd
Round Rock, TX 78681
ISO 9001:2015 and ISO 13845 Certified

4302 Stone Way North
Seattle, WA 98103