DMLS Printing Service

Q: Are DMLS parts actually as strong as CNC machined parts?

Yes. Unlike traditional casting, DMLS parts achieve >99.8% density. Because the metal is fully melted and fused at the microscopic level, the resulting mechanical properties (Yield Strength, Tensile Strength) meet or exceed ASTM standards for cast and wrought metals. The grain structure is completely isotropic.

Q: Can you print internal threads, or do they need to be machined?

We strongly advise against printing functional threads. While it is technically possible for large threads, the surface roughness of DMLS will cause binding and galling. Our Standard Practice: We print pilot holes to a near-net shape and then CNC tap the threads or install helical inserts (e.g., Helicoils) post-build. This guarantees strict dimensional accuracy and thread strength.

Q: DMLS is expensive. How can I design my part to reduce costs?

In CNC machining, complexity drives cost. In DMLS, machine time (Z-height) and material volume drive cost. To save money:Hollow out solid blocks (ensure you add powder escape holes).Redesign to minimize the need for support structures.Orient the part to minimize its overall height in the Z-axis. Our engineers can assist with this during the DFM review.

Engineering Specifications for Our DMLS Printing Service

DMLS is a powerful technology, but it is not a magic bullet. Forcing the wrong manufacturing process onto your geometry leads to compromised part strength. To help you avoid this, ShinicoFab provides the unvarnished engineering reality of how Direct Metal Laser Sintering (often categorized alongside Selective Laser Melting (SLM)) compares to traditional methods.

Parameter	Specification	Engineering Notes
Max Build Volume	Mid-Size: 9.85” x 9.85” x 12.8” (250x250x325 mm) Large Format: 15.75” x 15.75” x 15.75” (400x400x400 mm)	Part orientation and support structures will affect the final usable envelope.
Standard Tolerances	±0.005”(0.127 mm) for the first inch. ±0.002”/inch for each additional inch.	Need a precision press-fit? CNC post-machining is available in-house for critical dimensions.
Min. Feature Size	0.015” (0.38 mm)	Recommended for positive features like pins and bosses.
Min. Wall Thickness	0.020” (0.50 mm)	Highly dependent on geometry, aspect ratio, and build orientation (the 45-degree rule).
Layer Resolution	20 µm to 60 µm	Tailored by our engineers to balance surface finish requirements with overall build speed.
Material Density	> 99.8% (Fully Dense)	Achieves mechanical properties (tensile & yield strength) comparable to wrought metals.

Match DMLS Materials to Your Application

Don’t compromise your design with the wrong alloy. We’ve bypassed generic spec sheets to map our metal powders directly to their engineering utilities. Match your exact temperature, stress, and corrosion requirements below.

Aluminum (AlSi10Mg)

Engineering Utility: Offers an exceptional strength-to-weight ratio and high thermal conductivity. It is widely used to consolidate complex, multi-part cast assemblies into a single, monolithic printed part.
Typical Applications: Aerospace housings, automotive heat exchangers, and lightweight structural brackets.

Titanium (Ti6Al4V Grade 5)

Engineering Utility: Delivers outstanding mechanical strength, extreme corrosion resistance, and low density. Crucially, it is bio-inert, making it the gold standard for human contact.
Typical Applications: DMLS 3D printing service for medical components (orthopedics), DMLS 3D printing for aerospace parts (fasteners), and high-performance motorsports components.

Stainless Steel (316L vs. 17-4 PH)

316L: Choose this for maximum corrosion resistance and ductility. Highly weldable. Ideal for marine environments, food processing equipment, and surgical instruments.
17-4 PH: Choose this when raw strength is required. It is martensitic and can be fully heat-treated to condition H900 to achieve extreme hardness and yield strength. Ideal for robust tooling and industrial jigs.

Inconel (718 & 625)

Engineering Utility: Nickel-based superalloys that maintain their tensile strength and resist creep at extreme operating temperatures (up to 700°C / 1300°F). Highly resistant to oxidation and corrosion.
Typical Applications: Jet engine turbine blades, rocket engine manifolds, and chemical processing valves.

Tool Steel (Maraging MS1 / 1.2709)

Engineering Utility: Known for ultra-high strength and wear resistance. In DMLS, it is primarily used to print parts with complex internal channels that cannot be drilled.
Typical Applications: Injection mold inserts with conformal cooling channels to dramatically reduce cycle times and minimize part warpage.

Copper (CuCrZr / Pure Copper)

Engineering Utility: Provides unparalleled thermal and electrical conductivity. DMLS unlocks complex internal lattice structures for maximum surface area and heat dissipation.
Typical Applications: Advanced heat exchangers, induction coils, and rocket thrust chambers.

Eliminating DMLS Porosity and Warping

Industrial metal 3D printing is notorious for internal voids and thermal warping if handled by amateurs. We eliminate these risks through strict metallurgical control.

In-Chamber Inert Gas Environment (Argon/Nitrogen)

The Reality: Oxygen is the enemy of molten metal. It causes oxidation, porosity, and brittle parts.
Our Process: All sintering occurs in a strictly controlled inert atmosphere (Argon for Titanium, Nitrogen for standard alloys) with oxygen levels maintained below 0.1%. This ensures perfect metallurgical fusion without contamination.

Mandatory On-Plate Thermal Stress Relief

The Reality: DMLS generates extreme localized heat, leading to severe residual internal stresses. Amateurs cut the part off immediately, causing severe thermal warping.
Our Process: Every single DMLS part undergoes a high-temperature thermal stress relief cycle in a vacuum furnace while still welded to the build plate. This permanently relaxes the molecular structure before removal, guaranteeing absolute dimensional stability.

100% Isotropic Grain Structure

The Reality: Extruded 3D printing (FDM) suffers from delamination (weakness in the Z-axis).
Our Process: DMLS is not gluing layers; it is micro-welding. The laser creates a melt pool that fully penetrates the previous layer, resulting in an isotropic grain structure. Your part will exhibit uniform tensile strength and yield stress in the X, Y, and Z directions—matching or exceeding cast equivalents.

Hard-Data Inspection & Traceability

We don’t rely on visual checks. We validate tolerances and material composition using industrial-grade metrology:

Dimensional Verification: Hexagon/Zeiss CMMs (Coordinate Measuring Machines) and high-resolution Blue Light 3D Scanners for complex organic geometries.
Material Traceability: Certificates of Analysis (COAs) and Full Material Traceability reports are provided with your shipment, satisfying AS9100D, ISO 13485:2016, and ISO 9001:2015 requirements.

Finishing DMLS Parts for Final Assembly

Raw metal 3D printed parts do not come out of the printer ready for precision press-fits or high-pressure seals. To bridge the gap between a rough printed blank and a functional component, we provide a complete suite of post-processing for DMLS metal parts.

Standard As-Built Finish (Ra 200–400 µin / 5–10 µm)

The Reality: Straight off the machine, DMLS parts have a matte, micro-textured surface resembling a sugar cube or fine sand casting.
Best For: Internal structural brackets or components where aesthetics and tight mating surfaces are not a requirement.

Media Blasting (Our Default Finish)

The Process: We utilize automated glass bead or aluminum oxide blasting. This safely removes all loose, un-sintered powder and knocks down the sharpest microscopic peaks.
The Result: A clean, uniform satin finish. This is the standard baseline for 90% of structural applications.

Hybrid Manufacturing (CNC Post-Machining)

The Process: DMLS is incredible for complex geometry, but it cannot print a precision bearing press-fit. Our solution? We print your part to a near-net shape to save expensive material, and then use our in-house 5-axis CNC mills and lathes to finish critical features.
The Result: We hit strict tolerances of ±0.001” (0.025 mm) on critical bores, tapped threads, and highly critical sealing faces.

Advanced Metallurgy (HIP & Heat Treatment)

The Process: For mission-critical components, standard stress relief isn’t enough. We offer Hot Isostatic Pressing (HIP) and AMS 5663 Heat Treatment for extreme durability.
The Result: By subjecting the part to extreme heat and high-pressure Argon gas, HIP collapses any remaining internal micro-voids, dramatically increasing the material’s fatigue life and impact toughness.

Internal Channel Smoothing & Polishing

The Process: For complex conformal cooling channels or fluid manifolds, we utilize Abrasive Flow Machining (Extrude Honing) to smooth internal pathways that tools cannot reach.
The Result: Reduced fluid friction and pressure drops. Manual mechanical polishing is also available for exterior aesthetic or hygienic requirements (e.g., medical tools).

DfAM Guidelines for DMLS

A successful DMLS build starts in your CAD software. To optimize design for metal 3D printing, you must realize it isn’t just about creating topology optimized metal parts or complex lattice structures; it’s about respecting the physical limits of metal powder bed fusion.

The 45-Degree Rule & Support Structures

The Constraint: DMLS is a metal powder bed fusion process. Any downward-facing surface angled at less than 45 degrees relative to the build plate will require sacrificial support structures to anchor the part and dissipate thermal stress (preventing curling).
What You Need to Know: Our technicians manually remove all supports after the stress-relief cycle. However, support removal leaves behind “witness marks” (a slightly raised, rougher texture).
Pro-Tip: Design self-supporting angles (chamfers over fillets) and avoid placing critical mating surfaces or cosmetic faces on downward-pointing orientations.

Hollow Enclosures & Powder Evacuation

The Constraint: Un-sintered metal powder acts as the support medium during the build. If you design a fully enclosed hollow structure to save weight, that un-sintered powder will be permanently trapped inside. Trapped metal powder is extremely heavy and completely defeats the purpose of light-weighting.
What You Need to Know: You must design escape holes (drain holes) into your CAD model.
Pro-Tip: Include at least two escape holes at the lowest/highest points of the cavity. We recommend a minimum hole diameter of 0.125” (3.175 mm) to ensure complete powder evacuation via media blasting.

Internal Channels & Conformal Cooling

The Constraint: DMLS is brilliant for complex fluid manifolds and conformal cooling, but small horizontal channels are prone to drooping at the top arch or fusing shut entirely due to the surrounding melt-pool heat.
What You Need to Know: For circular horizontal channels, keep the diameter above our minimum threshold of 0.060” (1.5 mm) to prevent internal clogging.
Pro-Tip: For larger horizontal passages, redesign the standard circular cross-section into a teardrop or diamond profile. This makes the top of the channel self-supporting (adhering to the 45-degree rule) and eliminates the need for internal supports, which are impossible to remove.

DMLS vs. Binder Jetting vs. CNC

Evaluating metal binder jetting vs DMLS printing or 5-Axis CNC? Stop forcing the wrong technology onto your geometry. Here is the unvarnished truth on how they compare.

Feature	Direct Metal Laser Sintering (DMLS)	Metal Binder Jetting	5-Axis CNC Machining
Core Mechanism	Laser fusion of metal powder bed.	Liquid binder jetted onto powder, followed by furnace sintering.	Subtractive cutting from a solid metal billet.
Material Density & Strength	99.8% (Fully Dense). Isotropic properties matching wrought metals.	~95-99%. Lower tensile strength. Often requires bronze infiltration.	100% Solid.Maximum raw material strength.
Geometry & Complexity	Limitless. Ideal for internal channels, lattices, and organic DfAM shapes.	High-Pressure Water Jets. Withstands powerful 12.5mm nozzle jets (100kPa) at 100 liters/minute.	High. Good for complex shapes, but vulnerable to slumping during sintering.
Dimensional Accuracy	High (±0.005”). Requires CNC post-machining for press-fits.	Moderate. Sintering causes ~15-20% shrinkage, making tight tolerances difficult.	Ultimate (±0.001” or better).The gold standard for precision.

The Engineering Verdict

Choose CNC Machining for simple geometries, large flat surfaces, and strict GD&T tolerance requirements.
Choose Metal Binder Jetting for high-volume, cost-sensitive, non-load-bearing components.
Choose DMLS for functional, load-bearing aerospace and medical parts featuring complex, internal geometries (like conformal cooling) that are physically impossible to machine.

Frequently Asked Questions

We don’t hide behind marketing speak. Below are the unvarnished, technical answers from our shop floor regarding structural integrity, post-machining limitations, and cost-reduction strategies. Read these to avoid common DfAM pitfalls before finalizing your CAD.

Are DMLS parts actually as strong as CNC machined parts?

Yes. Unlike traditional casting, DMLS parts achieve >99.8% density. Because the metal is fully melted and fused at the microscopic level, the resulting mechanical properties (Yield Strength, Tensile Strength) meet or exceed ASTM standards for cast and wrought metals. The grain structure is completely isotropic.

Can you print internal threads, or do they need to be machined?

We strongly advise against printing functional threads. While it is technically possible for large threads, the surface roughness of DMLS will cause binding and galling. Our Standard Practice: We print pilot holes to a near-net shape and then CNC tap the threads or install helical inserts (e.g., Helicoils) post-build. This guarantees strict dimensional accuracy and thread strength.

DMLS is expensive. How can I design my part to reduce costs?

In CNC machining, complexity drives cost. In DMLS, machine time (Z-height) and material volume drive cost. To save money:

Hollow out solid blocks (ensure you add powder escape holes).
Redesign to minimize the need for support structures.
Orient the part to minimize its overall height in the Z-axis. Our engineers can assist with this during the DFM review.

What if my part exceeds your maximum build envelope?

DMLS metal is true metallurgical metal. If your part is too large for our EOS M400 machines, we can strategically section your CAD model, print the components separately, and seamlessly join them using standard TIG or Electron Beam Welding (EBW). The joined part will function exactly like a solid piece.

Can DMLS parts be conventionally heat-treated, machined, or coated after printing?

Absolutely. Once the part leaves the printer and undergoes initial stress relief, it behaves exactly like billet stock. We routinely perform CNC post-machining, H900 heat treatments (for 17-4 PH stainless), Hot Isostatic Pressing (HIP), and standard platings or anodizations.

Start Your Build: Secure Quoting & Direct Engineering Support

Stop dealing with automated quoting black holes. Upload CAD files (STEP/IGES) to our ITAR Compliance protected platform, collaborate with DMLS engineers, and get an instant quote. Whether you need a single prototype or low volume metal production parts with DMLS, you will receive fixed pricing and direct technical feedback from the shop floor.

DMLS Printing Service

Engineering Specifications for Our DMLS Printing Service