SLS — Selective Laser Sintering
Nylon SLS 3D printing for functional parts and short runs
Sintered PA12 parts with near-isotropic strength, no support marks and unit costs that scale from a single prototype to a 500-piece batch. Engineering review before quoting, files under NDA on request.
Typical dimensional accuracy
- 1Upload STEP / STL and specify quantity
- 2Engineering review and DFAM feedback (same day)
- 3Nested build, sintering and depowdering
- 4Bead blast, optional dye or machining, shipped worldwide
Quick answer
SLS (Selective Laser Sintering) uses a CO2 laser to fuse nylon powder layer by layer. There are no support structures, so complex geometries and nested batches print in the same envelope. Choose SLS for functional prototypes, living hinges, snap-fits, ductwork and low-to-mid volume production in PA12, PA12 GF or PA11. Typical tolerance is ±0.3% with a 0.3 mm minimum wall.
Applications
What SLS is good for
SLS is our go-to process when a nylon part has to actually work — not just look like a prototype.
- Functional prototypes with living hinges and integrated snap-fits
- End-use enclosures, housings and covers for industrial equipment
- Ducting, manifolds and airflow parts with internal channels
- Jigs, fixtures and assembly aids where FDM is too weak
- Spare parts on demand for out-of-stock components (10–500 units)
- Robotics and drone brackets that need light weight + real strength
- Consumer product short runs (50–1,000 units) before injection tooling
- Complex lattice structures for weight reduction
- Threaded parts (with heat-set inserts) for repeated assembly
Process
How SLS works
Four stages from your STEP file to a shipped batch.
File prep and nesting
Your STEP or STL is oriented, checked for minimum wall (0.7 mm safe), and nested with other parts to maximise packing density.
Powder bed sintering
The build chamber preheats to ~170°C. A CO2 laser traces each layer, fusing PA12 particles. Layer height is 100–120 µm.
Cool-down and depowdering
The full cake cools slowly (8–12 hours) to prevent warp. Parts are extracted, bead blasted and unused powder screened for reuse.
Finishing and QC
Standard blast finish, optional dye, vapor smoothing or CNC post-op. Dimensional check on critical features before dispatch.
Specs
Materials and specifications
Materials
- PA12 (Nylon 12) — general purpose, ~48 MPa tensile, low moisture uptake, chemically resistant. Our default SLS material.
- PA12 GF (glass-filled) — ~51 MPa tensile, ~3,200 MPa modulus, higher stiffness and heat deflection (~157°C HDT). Use for structural brackets and jigs.
- PA11 — bio-based, ~48 MPa tensile but 45–50% elongation. Best impact resistance in the SLS family, ideal for snap-fits and living hinges.
- TPU (Shore 88A) — flexible SLS on selected machines. For gaskets, grips, protective cases.
Key specs
- Build volume (standard)
- 380 × 280 × 380 mm
- Layer height
- 100–120 µm
- Min wall thickness
- 0.7 mm (1.0 mm recommended)
- Min feature size
- 0.5 mm (details), 0.3 mm (text)
- Dimensional accuracy
- ±0.3% (min ±0.3 mm)
- Surface finish
- Matte, Ra ~5–10 µm
- Colour
- Natural white, or dyed
Case example
Typical case: robotics bracket short run
A robotics integrator needed 240 mounting brackets to hold a sensor assembly at a fixed angle on a mobile platform. Injection molding was not viable (design changes still expected, quantity below break-even). Aluminium machining came in at €62 per part with a 3-week lead time.
We printed the batch in PA12 GF, nested across two builds, bead-blasted and dyed black. Result: €17.40 per part, 7 working days, weight 38% lower than the aluminium version, and passed a 5 kg drop test after installation.
Decision
When to choose SLS vs alternatives
- vs FDM: choose SLS when the part must be near-isotropic, watertight or has complex internal geometry FDM cannot support.
- vs SLA/DLP: choose SLS when parts see repeated mechanical load or impact — SLA resins are brittle by comparison.
- vs MJF: choose SLS when you need dyed colours other than black/grey, glass-filled PA12 GF, or lower cost on partial builds.
- vs CNC machining: choose SLS when geometry is too complex, batch size is 20–500 and material can be nylon.
- vs injection molding: choose SLS for volumes under ~2,000 parts, or when the design is still iterating and tooling is premature.
- vs metal 3D printing: choose SLS when metal-level strength is not required — nylon parts are 6× lighter and 10× cheaper.
Not sure which fits your application? Look at functional parts, short runs or spare parts on demand for use-case guidance, or send us the STEP file for a review.
FAQ
SLS 3D printing FAQ
Both fuse nylon powder without support structures. SLS uses a CO2 laser to sinter each layer point by point. MJF (HP Multi Jet Fusion) uses a fusing agent + IR lamps to melt full layers at once, so it is typically faster on high-density builds and gives a slightly finer, darker surface. Mechanical properties are comparable for PA12. SLS is better when you need dye penetration, glass-filled PA12 (PA12 GF) or lower per-part cost on partial builds. MJF wins on throughput and dimensional consistency across a full batch.
Get an SLS quote in 24 hours
Upload your STEP or STL. Our engineers review geometry, suggest material and confirm price and lead time — no obligation.