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SLS · Selective Laser Sintering

Industrial SLS 3D printing in Brescia, Italy

SLS 3D printing (Selective Laser Sintering) uses a laser to selectively sinter polymer powder, layer by layer. It is the benchmark technology for additive production of short and medium runs: no supports required, ~85–90% mechanical isotropy, near-total geometric freedom and a professional surface finish. EptaPrint's SLS fleet offers a build volume of up to 330 × 330 × 565 mm, with a consistent finish and repeatability on prototypes and small batches. Main material: Nylon PA12, with PA11 and TPU options.

Max build volume

330 × 330 × 565 mm

Dimensional accuracy

±0.3% (minimum ±0.3 mm)

Minimum feature

0.5 mm

Layer thickness

0.1 mm

XY/Z isotropy

~85–90%

Surface finish Ra (as-built)

8–12 μm

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How SLS 3D printing works

For each layer, about 100 µm thick, with the nylon powder held just below its melting point:

  1. The roller spreads powder drawn from the feed pistons;
  2. The laser, steered by the scanner mirrors, sinters the cross-sections of the parts;
  3. The platform drops by one layer.

The unsintered powder supports the parts: no supports are needed, and many parts can be packed throughout the build volume, like the batch in the photo.

Batch of SLS 3D printed nylon components laid out on a workbench: drone frames, arms and covers

Key strengths

  • ~85–90% mechanical isotropy (vs. 70–80% for FDM)
  • No supports needed: total geometric freedom
  • Ideal for batches of 10 to 5,000 parts (pure additive production)
  • Uniform surface finish (Ra 8–12 μm as-built)
  • Nesting: many parts in a single build, lowering the unit cost

Typical applications

  • Short runs of end-use components (10–5,000 parts)
  • Housings, covers and functional cosmetic parts
  • Components with internal channels, lattices and snap-fits
  • On-demand spare parts for industrial machinery
  • Functional prototypes with the same properties as the injection-molded part

Compatible materials

NYLON PA12 POWDERTPU POWDER
See the materials catalog →DfAM design guide →

FAQ

Frequently asked questions

Frequently asked questions about industrial SLS 3D printing.

SLS is the better choice when you need mechanical isotropy, geometric freedom (internal channels, lattices) and a uniform finish, or intermediate quantities (10–5,000 parts). FDM remains preferable for high-performance polymers (PEEK, Ultem) and for large one-off parts.

As-built, the SLS surface is slightly porous. For fluid-tight or gas-tight applications we apply a sealing treatment (vapor smoothing, resin infiltration or painting), achieving a pressure tightness that is sufficient for many industrial applications.

SLS is competitive with injection molding up to 500–2,000 parts, depending on geometric complexity. Above that volume injection molding remains cheaper; below it, SLS eliminates €5,000–20,000 of tooling.

Planning an SLS project? Let's talk.

Upload your CAD: within 24 hours we reply with a quote, a lead time and DfAM recommendations optimized for SLS.

Request a quote