For SLS, 1.0 mm is the minimum for non-loaded structures, 1.5-2.0 mm under mechanical load. Below 0.8 mm risks deformation or powder breakthrough. For Carbon LW and PA802CF (fibre-reinforced), 2.0 mm is the practical minimum; fibre orientation around a thin wall gives unpredictable strength.
Why there is a minimum at SLS
SLS builds in 0.1 mm layers. Each layer must fuse to the previous and stay mechanically stable when the powder roller lays the next.
At walls below ~0.8 mm there is not enough material to absorb those forces. The wall shifts, deforms or cracks. Also thermally: thin walls cool faster than surrounding structures, causing internal stress and warping.
Starting wall thickness per material
PA12 – 1.0 mm for non-load panels. 1.5-2.0 mm under load.
PA11 – Same range as PA12, with a bit more headroom thanks to higher elongation.
Carbon LW and PA802CF – Absolute minimum 1.5 mm, practical 2.0 mm. Fibres around a thin wall do not orient ideally, effective strength drops quickly.
TPU 1301 (flexible) – 1.5 mm minimum. Thin TPU sections can tear during de-powdering.
How to verify wall thickness in your CAD
All major CAD packages (SolidWorks, Fusion 360, Inventor, NX) have a wall thickness or minimum wall analysis built in. Run it before you request a manufacturability check.
If unsure: upload the STEP and ask our engineers for a DfAM check. We advise per zone on wall thickness, rib patterns and shell options to balance weight and strength.