ISO 9001 & AS9100 Certified SLS 3D Printing Facility
SLS 3D Printing Service
Get functional nylon parts in as little as 3 days with no minimum order quantity. Our SLS 3D printing service delivers PA12, PA11, glass-filled nylon, and TPU parts with tolerances to ±0.2 mm — from one prototype to 1,000 production units.
At Baetro, our Qingdao facility operates industrial SLS printers capable of producing complex geometries without support structures. Selective Laser Sintering fuses nylon powder layer by layer, creating strong, durable parts ideal for functional prototypes, end-use production, and complex assemblies.
±0.2 mm
Printing tolerance
3–7 days
Standard lead time
Free DFM
On every quote
MOQ 1
Prototype to production
Powder Bed Fusion Fundamentals
What Is Selective Laser Sintering?
Selective laser sintering (SLS) is a powder bed fusion additive manufacturing process that uses a high-powered laser to fuse thermoplastic powder particles layer by layer. Unlike FDM or SLA, SLS does not require support structures. The unsintered powder surrounding each part acts as natural support, enabling complex geometries, internal channels, and moving assemblies in a single build.
The process begins with a thin layer of heated nylon powder spread across the build platform. A CO₂ laser traces the cross-section of the part, sintering the powder into a solid layer. The platform lowers, a new powder layer is applied, and the process repeats until the part is complete. After printing, parts cool inside the build chamber — typically 8 to 12 hours for full thermal stability — then undergo depowdering and any requested post-processing.
Support-Free Complexity
Unsintered powder supports overhangs, internal channels, and moving assemblies
Isotropic Strength
Parts have consistent mechanical properties in all directions
No Tooling Required
Ideal for functional prototyping and end-use production
Nylon-Based Materials
Durable, chemically resistant thermoplastics for real-world applications
Bridge to Production
Validates fit, form, and function before injection mold tooling. Perfect for low-volume end-use parts.
Materials Library
SLS Materials and Their Properties
Material selection determines how your part performs under load, temperature, and environmental exposure. We offer three standard SLS materials, each optimized for specific applications.
General purpose
PA12 (Nylon 12)
Most widely used SLS material. Excellent balance of strength, stiffness, and chemical resistance. Tensile strength: 45 MPa, elongation: 9–15%. Minimal moisture absorption for consistent dimensional stability.
- Best for: General-purpose functional parts, enclosures, brackets, housings, mechanical assemblies
- Key advantage: Consistent dimensional stability across different environments
High impact
PA11 (Nylon 11)
Higher impact resistance and flexibility than PA12. Derived from castor oil — renewable-content option. Elongation at break: 25–40%, ideal for repeated bending or impact without cracking.
- Best for: Living hinges, snap fits, impact-resistant components, parts requiring flexibility under load
- Key advantage: Bio-based renewable content option
Stiff & heat-resistant
Glass-Filled PA12
30–40% glass beads in nylon matrix. Stiffer with higher heat deflection temperature: 160°C vs 110°C standard. Tensile modulus increased ~60%, elongation drops to 3–5%.
- Best for: Structural components, high-temperature applications, parts requiring minimal deflection under load
- Key advantage: Higher stiffness and heat resistance than standard PA12
Capabilities
SLS Capabilities and Specifications
Understanding SLS capabilities helps you design parts that print reliably without surprises. Here are the specifications we deliver consistently across every order.
Dimensional Accuracy
±0.2 mm for parts up to 100 mm; ±0.3% for larger components. Tighter tolerances are available on request for critical dimensions.
Layer Thickness
0.08–0.15 mm depending on material and finish requirements. Thinner layers produce smoother surfaces but extend build time.
Build Volume
Our industrial SLS systems accommodate parts up to 400 × 400 × 450 mm. For larger geometries, splitting into sections or post-assembly finishing is recommended.
Minimum Feature Size
0.5 mm for walls, 0.8 mm for embossed or engraved details, and 1.0 mm for holes to ensure powder removal.
Surface Finish
As-printed parts have a matte, slightly grainy texture (Ra ~8–12 μm). Post-processing options include media blasting, vapor smoothing, and priming to reduce Ra to 3–6 μm.
Part Nesting & Batch Efficiency
Multiple parts nest together in the build chamber. Printing 10 parts typically takes marginally longer than printing one — making SLS highly cost-effective for small production runs. Every part is CMM-inspected with full dimensional reports.
Procurement confidence
Why Choose Baetro for SLS 3D Printing
Most SLS service providers treat printing as a transaction — upload a file, receive a part, move on. We treat it as an engineering partnership.
Service Advantages
- Instant Quotes, Transparent Pricing: Upload your .stl or .step file and receive a live quote in under 60 seconds. No hidden setup fees. Quote shows material, build time, post-processing, and shipping line by line.
- Free DFM Feedback on Every Order: Our engineers review every CAD file before production. Flag wall thickness issues, missing escape holes, and orientation opportunities. Most customers see 10–20% cost reduction — at no charge.
- No Minimum Order Quantity: Order one part or 1,000 parts. Same process regardless of quantity. Five prototypes for a design review without paying prototype shop premiums.
- 3–7 Day Standard Lead Times: Parts ship in 3–7 days from order confirmation. Expedited options for urgent prototypes. Real-time order tracking from build start through shipment.
Quality & Capabilities
- Certified Quality Systems: ISO 9001:2015 and AS9100 certified. Every part inspected on CMM with full dimensional reports. Material traceability from powder lot to finished part.
- Multi-Process Continuum: SLS is one capability in a broader ecosystem. Transition to CNC machining for tighter tolerances, injection molding for high-volume production, or sheet metal fabrication for enclosures.
- Global Capability, Local Service: From our ISO-certified facility in Qingdao, we ship worldwide. Dedicated project manager communicates in English with real-time updates — overseas cost advantage with local responsiveness.
Applications
Applications and Industries for SLS
SLS serves a wide spectrum of applications across industries that demand functional parts without the upfront investment of injection mold tooling.
Application
Low-to-Mid Volume Production
For 10–1,000 units, SLS outperforms injection molding on total cost. No mold tooling to amortize. Batch nesting keeps per-part costs low — ideal for bridge manufacturing while steel molds are fabricated.
Application
Complex Geometries
Internal channels, lattice structures, and interlocking assemblies print without supports. Integrated living hinges, conformal cooling channels, and topology-optimized lightweight structures.
Application
Jigs, Fixtures & Tooling
Print custom fixtures in PA12 rather than machining from aluminum. Durable for production use, cost a fraction of machined equivalents, and easily redesigned when line changes occur.
Industry
Aerospace
Lightweight ducting, brackets, and interior components where weight reduction matters. Functional prototypes for flight-ready testing.
Industry
Automotive
Functional prototypes, intake manifolds, and custom tooling for assembly lines. Rapid iteration without hard tooling commitments.
Industry
Medical Devices
Surgical planning models, prosthetic components, and biocompatible-grade PA11 parts. Patient-specific devices printed on demand.
Technology Comparison
SLS vs Other 3D Printing Technologies
Not every project belongs in SLS. Understanding how selective laser sintering compares to FDM, SLA, and Multi Jet Fusion (MJF) helps you choose the right process for your part geometry, material requirements, and budget.
| Factor | SLS | FDM | SLA | MJF |
|---|---|---|---|---|
| Material | Nylon powder (PA12, PA11, TPU) | Thermoplastic filament (ABS, PLA, PETG) | Liquid photopolymer resin | Nylon powder (PA12, PA11) |
| Supports | Self-supporting (powder bed) | Required | Required | Self-supporting (powder bed) |
| Strength | Isotropic, functional end-use | Anisotropic, weaker along Z-axis | Brittle, limited durability | Isotropic, slightly higher density |
| Surface Finish | Matte, slightly grainy | Visible layer lines | Very smooth, glossy | Smoother than SLS, denser |
| Accuracy | ±0.2–0.3 mm | ±0.3–0.5 mm | ±0.1–0.2 mm | ±0.2 mm |
| Best For | Functional prototypes, low-volume production | Quick drafts, concept models | High-detail models, visual prototypes | Batch production, smooth finishes |
| Lead Time | 3–7 days | 2–5 days | 3–7 days | 3–7 days |
The right finish depends on function, environment, and appearance requirements. During DFM review, our engineers recommend finishes based on your application so you avoid unnecessary treatments and late-stage protection issues.
Prototypes & Production
CNC Milling for Prototypes & Production
CNC milling enables a seamless transition from prototype to production—same process, same quality, scaled to your volume.
Prototype CNC Milling
Fast parts for design validation without tooling commitments.
- No minimum order quantity—order 1 piece
- 3–7 day standard lead times
- Same tolerances and quality as production parts
- Free DFM feedback for manufacturability issues
- Multiple material options for design comparison
Low-Volume Production
10–1,000 parts with cost-effective CNC milling and flexible scheduling.
- Economical for volumes up to 1,000+ parts depending on complexity
- Consistent quality across batches with documented processes
- Easy design changes between runs without tooling modification
- Ideal for product launches, limited editions, and bridge production
High-Volume CNC Milling
Optimized programs, in-process inspection, and dedicated machine capacity ensure throughput for larger production runs.
- Cycle time optimization for high-volume efficiency
- In-process and final inspection routines
- Dedicated machines for consistent throughput
Design guidelines
Design Guidelines for SLS Parts
Designing for SLS requires different thinking than designing for CNC machining or injection molding. These guidelines help you avoid common pitfalls and reduce cost without sacrificing function.
Wall Thickness
Minimum wall thickness: 0.5 mm for short spans, 1.0 mm for larger surfaces. Walls below 0.5 mm may warp or fail during depowdering. Use ribs or lattice infill for stiffness at minimum weight.
Escape Holes
Hollow parts trap unsintered powder inside. Include at least one escape hole (minimum 5 mm diameter) to allow powder removal. Multiple holes for large volumes. Trapped powder adds weight and uneven cooling stresses.
Shrinkage & Warping
Nylon shrinks approximately 2–3% during cooling. Design with shrinkage in mind or specify critical dimensions for post-build machining. Large flat surfaces prone to warping — add ribs or curve the surface.
Oversintering
Small features adjacent to thick sections can absorb excess thermal energy. Maintain minimum 1.0 mm gap between fine features and thick walls. Embossed details are more reliable than engraved details below 0.5 mm depth.
Tolerance Specifications
General: ±0.2 mm or ±0.3% of dimension. Hole diameters: +0.1 / −0.2 mm. Threaded features: design for self-tapping inserts rather than printed threads — printed threads lack precision for reliable assembly.
Nesting & Build Orientation
Our operators optimize nesting to maximize build chamber utilization, reducing per-part cost. For critical surface finish on one face, mention in quote notes and we will orient accordingly.
Technology comparison
SLS vs. FDM vs. SLA vs. MJF
Understanding how selective laser sintering compares to other 3D printing technologies helps you choose the right process for your part geometry, material requirements, and budget.
SLS vs. FDM
FDM extrudes molten filament through a nozzle, producing visible layer lines and anisotropic strength — parts are weaker along the Z-axis. SLS produces isotropic parts with no layer-line visibility and no support scars.
- Choose SLS for: Functional prototypes that must endure mechanical testing
- Choose FDM for: Quick concept models where appearance matters less than speed and cost
SLS vs. SLA
SLA produces exceptionally smooth surfaces with fine detail resolution, ideal for visual prototypes and master patterns. However, SLA resins are generally more brittle than SLS nylons and can degrade under prolonged UV exposure.
- Choose SLS for: Parts that snap together, bear load, or survive in industrial environments
- Choose SLA for: Detailed aesthetic models or investment casting patterns
SLS vs. MJF
Multi Jet Fusion uses inkjet-printed agents rather than a laser. MJF produces smoother surfaces and faster throughput for dense builds. SLS offers larger build volumes, broader material diversity (glass-filled nylon, TPU), and more established process parameters.
- Choose SLS for: Larger parts, specialized materials (glass-filled, TPU), max build volume
- Choose MJF for: Smoothest surface finish on standard PA12/PA11, medium-sized batches
Post-processing
Post-Processing Options for SLS Parts
As-printed SLS parts are functional but may require finishing for aesthetic or performance requirements. We offer several post-processing options in-house.
- Standard Finish (Media Blasted)
Parts are depowdered and media blasted to remove surface powder residue. Uniform matte finish with slightly reduced roughness. Default finish — adds minimal cost and lead time. - Dyeing
PA12 and PA11 parts accept dye uniformly. Standard colors: black, grey, blue. Custom colors for production quantities. Note: deep scratches may expose white core material. - Vapor Smoothing
Solvent vapor slightly melts the surface, filling micro-pores. Smoother, glossier finish with improved sealability and reduced moisture absorption. Ideal for fluid-contact parts and consumer-facing products. - Priming & Painting
Primer and automotive-grade paint applied for specific colors or textures. Enables exact color matching and textured finishes that mimic injection-molded surfaces. Adds 1–2 days to lead time. - Polishing
Selective surface polishing for areas requiring optical smoothness or minimal friction. Applied to sealing surfaces or bearing interfaces rather than entire parts.
FAQ
Frequently Asked Questions
Answers to common questions about SLS 3D printing tolerances, materials, costs, lead times, and post-processing options.
What Is SLS 3D Printing and How Does It Work?
Selective laser sintering uses a CO₂ laser to fuse thermoplastic powder particles layer by layer inside a heated build chamber. No support structures are needed because unsintered powder surrounds and supports the part during printing. After the build completes, parts cool for 8–12 hours before depowdering and post-processing.
What Materials Are Available for SLS 3D Printing?
Our standard SLS materials include PA12 (general-purpose nylon), PA11 (impact-resistant, flexible), glass-filled PA12 (stiff, high-temperature), and TPU (rubber-like elastomer). Our engineers recommend the optimal material based on your requirements.
How Much Does SLS 3D Printing Cost?
Small prototypes: $15–$30 per part (single unit). Production runs of 10 units: $8–$15 each. Production runs of 100+ pieces: $5–$25 per part depending on geometry and nesting efficiency. Upload your .stl file for an exact instant quote.
What Is the Difference Between SLS and MJF?
Both are powder bed fusion processes. SLS uses a laser to sinter powder. MJF uses inkjet-printed fusing agents activated by infrared lamps. MJF produces smoother surfaces and faster throughput for dense builds. SLS offers larger build volumes and more material options.
Do SLS Parts Require Support Structures?
No. The unsintered powder in the build chamber acts as natural support, allowing complex geometries, internal channels, and overhangs to print without dedicated support material — a primary advantage over FDM and SLA.
What Tolerances Can SLS 3D Printing Achieve?
Standard tolerances: ±0.2 mm for dimensions under 100 mm, ±0.3% for larger parts. Tighter tolerances achievable through post-build machining or process parameter optimization. Every part inspected on CMM with full dimensional reports.
How Long Does SLS 3D Printing Take?
Standard lead time: 3–7 days from order confirmation to shipment. Build time: 10–20 hours for a full chamber. Cooling adds 8–12 hours. Post-processing adds 1–2 days depending on finish selected.
Is SLS Suitable for Production Parts or Just Prototyping?
SLS works for both. It excels at functional prototyping because parts match molded nylon properties closely. For production, SLS is cost-effective from 10 to approximately 1,000 units — an economical alternative to injection molding when tooling investment is not justified.
What Post-Processing Options Are Available?
Standard finishes: media blasting for uniform matte surfaces. Optional upgrades: dyeing (black, grey, blue), vapor smoothing for reduced roughness and improved sealability, priming and painting for color-matched aesthetics, and selective polishing for critical surfaces.
Can You Print Large Parts with SLS?
Yes. Our industrial SLS systems accommodate parts up to 400 × 400 × 450 mm. For larger geometries, we can design multi-part assemblies with integrated alignment features or recommend CNC machining for post-assembly finishing.
Quote-ready manufacturing
Get SLS Parts in 3–7 Days — Upload Your File Now
Selective laser sintering gives you functional nylon parts without mold tooling, support structures, or minimum order requirements. Whether you need one prototype to validate a living hinge or 500 production housings for a consumer product launch, our SLS 3D printing service delivers.
Upload your .stl or .step file for an instant quote with live pricing, material recommendations, and free DFM feedback from our engineering team. Most quotes arrive in under 60 seconds. Parts ship in 3–7 days standard, with full CMM inspection reports included.
Questions about material selection, design optimization, or production scaling? Contact our engineering team — we respond within 24 hours. No minimum order quantity. ISO 9001 & AS9100 certified.