Selective Laser Sintering — no support structures, no compromises on geometry, and production-grade mechanical properties in Nylon and TPU. The industrial standard for functional end-use parts.
Get an SLS Quote Compare TechnologiesSelective Laser Sintering (SLS) uses a high-power laser to selectively fuse (sinter) powder material — typically Nylon 12 — in a powder bed. The laser scans each cross-section of the part, fusing the powder particles together. After each layer, a roller spreads fresh powder over the build, and the process repeats. The surrounding unfused powder supports the part during the build, eliminating the need for support structures entirely.
This support-free process is SLS's defining advantage. It means parts with internal channels, interlocking mechanisms, complex undercuts, lattice structures, and nested assemblies can be produced without the design compromises that support removal imposes on FDM and SLA. Geometries impossible or impractical with other technologies are routine with SLS.
SLS Nylon (PA12) is a genuine engineering thermoplastic with mechanical properties approaching injection-molded Nylon. Parts are chemically and physically consistent throughout — no anisotropy, no weak interlayer boundaries, no visible layer lines. SLS is the preferred technology for functional end-use parts, production components, and any application where geometry complexity and material performance need to coexist.
| Material | Tensile Strength | Elongation at Break | Best For |
|---|---|---|---|
| Nylon 12 (PA12) | 48 MPa | 18% | General functional parts, snap fits, enclosures |
| Nylon 12 Glass-Filled (PA12-GF) | 60 MPa | 8% | Stiff structural parts, low creep, tooling |
| Nylon 11 (PA11) | 50 MPa | 40% | Flexible-but-strong parts, ducts, living hinges |
| TPU Powder | 6 MPa | 350% | Flexible parts, footwear, gaskets, cushioning |
| Nylon 12 Alumide (Al-filled) | 48 MPa | 4% | Metallic appearance, stiff, good thermal conductivity |
Raw SLS parts have a fine, slightly grainy surface with a matte natural-white or gray appearance. The texture is functional and acceptable for many end-use applications, but we offer multiple finishing options for improved aesthetics.
Parts are removed from the powder cake, cleaned, and bead blasted for a uniform matte surface. The natural finish for functional end-use parts where appearance is secondary to function. Fastest and lowest-cost option.
SLS Nylon accepts dye uniformly, unlike FDM where color only affects the surface. Parts can be dyed solid colors that penetrate throughout the material — scratches and cuts don't reveal a different color inside. Standard colors available; custom Pantone dyeing on request.
Chemical vapor smoothing process reduces surface roughness by up to 65%, creating a near-smooth surface similar to injection-molded Nylon. Improves watertightness, reduces friction, and significantly improves aesthetics for consumer-facing parts.
Primer and color coat applied over the SLS surface for specific color requirements. Works well with vapor-smoothed parts as a base. Multiple color and finish options — matte, satin, gloss, metallic, and textured finishes available.
Protective epoxy coating improves chemical resistance, reduces moisture absorption, and enhances surface hardness for demanding functional applications. Clear or tinted options available.
Metallic spray coating over Alumide-filled SLS parts creates a convincing machined-aluminum appearance while retaining the complex geometry advantages of 3D printing.
Channels, lattices, internal cavities, and undercuts that would require extensive, part-damaging supports in FDM or SLA. SLS's powder bed provides support everywhere, enabling design freedom unavailable in any other technology.
Chains, hinges, gears, and printed-in-place assemblies can be built as single prints with SLS. The unfused powder acts as clearance material between moving parts — you simply shake or vacuum it out to reveal a moving assembly.
The SLS build chamber can be densely nest-packed with multiple parts simultaneously. For production quantities, this dramatically reduces per-unit cost and lead time compared to single-part FDM runs. Batch costs are shared across all parts in the build.
SLS Nylon is a genuine engineering material suitable for parts that must work — snap fits, spring mechanisms, wear surfaces, structural brackets. It's not a prototype material masquerading as something stronger.
Internal channels, manifolds, and complex fluid pathways printed as a single part without assembly. SLS produces truly watertight channels, especially after vapor smoothing or epoxy coating. Used for custom heat exchangers, pneumatic manifolds, and coolant routing.
TPU powder SLS produces flexible, durable wearable parts — custom orthotics, footwear midsoles, latticed cushioning structures, and ergonomic grips that balance stiffness and compliance in precisely controlled geometry.
SLS uses expensive industrial laser sintering machines with high operating costs — powder materials, laser maintenance, and longer print and cool-down cycles contribute to higher per-part pricing. However, SLS is often more cost-effective for complex geometries or production volumes because you can pack multiple parts in a single build, and you eliminate the manual labor of support removal. For the right application, SLS often has a lower total cost than it appears.
Correct. The powder bed itself supports the part during sintering — the laser-fused geometry is surrounded on all sides by unsintered powder, which holds everything in place without mechanical attachment. This means overhangs, complex undercuts, internal channels, and moving assemblies all emerge from the powder cake clean, without any support removal required. The only post-processing is depowdering (blowing out loose powder from cavities) and cleaning.
As-sintered SLS Nylon has a slightly porous microstructure that can allow liquid penetration under pressure. For fluid-carrying applications, we recommend vapor smoothing, epoxy coating, or a urethane seal coat to close the surface porosity. Treated SLS parts perform reliably in low-to-medium pressure fluid applications. For high-pressure or chemical-resistance requirements, contact us for a specific material recommendation.
Raw SLS has a finer, slightly grainy texture that is noticeably different from injection-molded Nylon. After vapor smoothing, the surface approaches injection-molded quality — particularly for interior and functional surfaces. Exterior show surfaces may still benefit from a light sand and paint for consumer-product applications. Mechanically and chemically, the performance of SLS PA12 is very close to injection-molded PA12.
SLS builds typically take 1–3 days of print time depending on the build height, followed by 12–24 hours of cool-down, plus depowdering and post-processing. Standard lead time is 3–5 business days from file approval to shipment. Rush processing is available. Because SLS requires a full powder bed to run efficiently, rush orders may be combined with other builds unless you require a dedicated build.
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