Our Direct Metal Laser Sintering (DMLS) design guidelines help engineers design metal parts that print reliably while maintaining structural integrity and dimensional accuracy. This guide covers critical considerations including wall thickness, support strategy, overhang angles, internal channels, and thermal stress management so components are manufacturable, mechanically robust, and ready for both functional prototypes and production-grade metal applications.
Build Volume
280mm x 280mm x 350mm
General Tolerance
±0.3% (min ±0.3 mm)
Min. Wall ThicknessMinimum Wall Thickness
1.0 mm
Min. Hole DiameterMinimum Hole Diameter
0.5mm
Direct Metal Laser Sintering (DMLS) uses a high-powered laser to selectively fuse metal powder particles layer-by-layer into dense, fully functional metal parts. This industrial-grade technology produces components in stainless steel, aluminum, and titanium with mechanical properties matching traditional manufacturing methods.
These DMLS design guidelines cover essential considerations for wall thickness, thermal management, support structures, and material-specific behaviors. Following these best practices ensures your metal parts achieve optimal strength, precision, and surface quality while minimizing distortion and post-processing requirements.
Varies by Material
Build volumes vary by material: Aluminum (AlSi10Mg) - 400mm x 300mm x 400mm (15.75" x 11.81" x 15.75"), Stainless Steel (316L) - 280mm x 280mm x 350mm (11.02" x 11.02" x 13.78"), Titanium (TC4) - 150mm x 150mm x 200mm (5.91" x 5.91" x 7.87").
NoteDifferent materials have different optimal build chamber sizes for quality and cost efficiency.
±0.3% (min ±0.3 mm)
Standard production tolerance is ±0.3% of feature size with a minimum of ±0.3 mm. If your parts require specific tolerances, an engineering drawing must be provided when requesting a manual quote. Secondary machining recommended for critical interfaces.
CriticalParts designed with thin, flat planes will likely warp, so this should be avoided if tight tolerances are required. Polishing removes approximately 0.1mm of material.
20 - 80 microns
Standard layer height varies by material. Fine layer heights provide better surface finish and detail resolution.
TipThinner layers improve surface quality but increase build time and cost.
Visible Layer Lines
Layer lines are visible on faces at a low angle relative to the build plate. Metal supports are removed, which may leave subtle marks in the surface of the part. Metal 3D printed parts are shot peened to a surface uniform roughness of 200 - 400 Ra after support removal.
NotePost-processing can significantly improve surface finish for critical applications.
Thicker geometries and walls with variable thickness are at risk of deformation due to shrinkage and stress. In general, follow wall design rules for injection molding to achieve a more uniform and consistent part.
1.0 mm (0.039")
Supported walls are connected to two or more sides and are thick enough to support the model.
CriticalThinner walls may warp or curl during the sintering process due to thermal stresses.
1.2 mm (0.047")
Unsupported walls are connected on only one side or edge.
CriticalUnsupported walls thinner than 1.2mm may sag or curl during the printing process.
1.5mm (0.059")
The minimum pin size depends on a combination of parameters such as; part orientation, nozzle diameter, and length of the pin.
Recommendations
The quality of engraved and embossed features depends heavily on part orientation and the resulting thermal effects of printing. Try to place fine details away from overhanging faces that require support, since touchpoints can interfere with intricate geometry.
Minimum depth: 0.5mm (0.019")
Debossed details are recessed features on your model. These features should be no shallower than 0.5mm (0.019").
TipAdd draft angles to debossed features for better definition and easier support removal.
Minimum depth: 0.5mm (0.019")
Embossed details are raised features on your model. We recommend a thickness of 1mm (0.039") & depth of 0.5 mm (0.019").
Recommendations
Minimum point size: 16pt
Minimum suggested text size on the top or bottom build plane of a DMLS model is 16 point boldface. Minimum suggested text size on vertical walls is 10 point bold.
Recommendations
The mechanical performance of printed assemblies is sensitive to variables such as print orientation, layer height and machine tolerances. It is best to test and refine any mated parts before committing to a full production run.
0.5mm (0.019")
Clearance is the distance between two moving parts on hinges, joints, mating parts, etc.
CriticalInsufficient clearance can cause parts to fuse together during the printing process.
0.3mm (0.004")
For a tight press fit, add a small offset, and chamfer the leading edge to ease entry. Always print an initial test part to dial in dimensions.
Recommendations
Minimum: 0.6 mm (0.023")
This defines the minimum allowed gap between a bush and a bolt, to avoid bonding of the hinge parts.
TipDMLS can print functional assemblies, but clearances must be carefully designed and tested.
Hole accuracy can vary depending on print orientation, thickness of surrounding material and support structures. For tight tolerances, consider printing center marks and post-machining them instead.
0.5mm (0.019")
Depending on orientation, circular holes can resolve as ovals – if higher accuracy is required, printing the hole smaller and then drilling it out is recommended.
NoteVertical holes print more accurately than horizontal ones due to layer stacking.
0.5mm (0.019")
Gaps or slots can fuse if made too narrow, and support material may be difficult to remove. If possible, orient gaps along the xy-plane for highest accuracy.
Recommendations
Geometry Dependent, Contact us for Details
Hollow features may be filled with support material, and must be designed with access holes so that the supports and powder can be removed during cleaning. Larger parts or parts with complex internal features may require larger or multiple holes to allow powder and support material to be fully removed.
TipSupports make complex internal geometries possible with proper drain hole design.
Part geometry can be optimized for 3D printing to reduce material usage, increase strength and rigidity, and take advantage of machine capabilities.
Design Recommendations
Fillets can be used to reduce stress concentrations and increase the strength of your part. When designing fillet features across inside and outside corners, it is best to have them share a common center point in order to maintain a consistent wall thickness.
Recommendations
Design Recommendations
Bosses and ribs are an effective way to add strength and stiffness to a part while keeping material consumption to a minimum, this can also reduce build time and use less support material.
Recommendations
DMLS Printing
Parts do not require physical support structures. Parts are supported by the surrounding powder in the build chamber. This powder material is removed using compressed air glass beads leaving no defects or residual powder on the final part.
NoteDMLS parts are self-supporting by nature, providing consistent mechanical properties throughout.
DMLS Printing
Infills are not applicable for DMLS 3D Printed parts. Walls are printed solid throughout.
NoteSolid metal construction ensures consistent mechanical properties throughout the part.
Threads and inserts can increase functionality of your parts, but keep in account that printed threads will wear down through repeated cycles of assembly and disassembly, while heat set inserts can potentially deform or cause imperfections on part finish due to the heat processes of installation.
DMLS Guidelines
We recommend M6 thread sizes or larger, and use thread profiles designed for plastics. The rough surface produced from DMLS printing will result in increased friction with connecting thread parts. We recommend using an offset of 0.5mm to compensate for thermal shrinkage.
Recommendations
DMLS Post-Processing
Design parts with holes sized for tapping, or center marks for drilling a pre-tapped hole. Tapping removes material, puts pressure on the surrounding geometry, and fastener locations are often points of stress, so make sure there is enough material surrounding the tapped hole.
CriticalEnsure adequate wall thickness around tapped holes to prevent cracking under stress.
DMLS Applications
Inserts are not required for DMLS parts.
NoteDMLS parts can be directly threaded or machined for fastening without inserts.
While printed parts are highly functional and accurate, there are a variety of ways to modify them after printing to enhance durability or aesthetics.
DMLS Post-Processing
Parts too big to fit on the print tray can be split in CAD and printed in multiple parts, then glued or press fit. Use joinery features, such as tongue and groove, to ensure the sections are aligned and bond tightly.
Recommendations
DMLS Machining
Parts can be machined to tighter tolerances using traditional or CNC subtractive manufacturing equipment.
TipSharp tools and proper speeds/feeds are important when machining DMLS parts.
DMLS Finishing
Parts can be sanded, primed, and painted for an excellent surface finish. Parts can also be coated with a lacquer, varnish or clear coat for various custom finishes.
Recommendations
DMLS Post-Processing
Not applicable for DMLS.
NoteDMLS parts achieve excellent surface finish through bead blasting and other mechanical processes.
