The designed distance between the outer and inner surfaces of a part wall: a critical design parameter that determines printability, strength, and material use.
Wall thickness (t) is the perpendicular distance between the inner and outer face of any thin section of a part. Minimum printable wall thickness depends on the process: FDM requires t ≥ 1× nozzle diameter (0.4mm for 0.4mm nozzle, but 2× is recommended for strength); SLA/MSLA requires t ≥ 0.5mm for supported walls, 1mm+ for unsupported; SLS requires t ≥ 0.7mm for structural sections. Design intent wall thickness must account for slicer perimeter multiplier and overlap settings.
In Fusion 360 and SolidWorks, use the 'Thickness Analysis' tool (colored map from minimum to maximum wall thickness) to validate design before printing. For FDM structural parts, target 2–4 perimeter walls (0.8–1.6mm at 0.4mm nozzle) plus infill. Thin walls below minimum resolve to either a single extrusion or are skipped entirely by the slicer, producing structural weak points invisible in the 3D view.
Slicer minimum wall thickness is determined by nozzle diameter, not the design CAD dimension: a 0.3mm designed wall will simply not print with a 0.4mm nozzle. Thin walls at feature transitions (bosses meeting base plate) are common stress failure points. Shell operations can inadvertently create zero-thickness walls at tight corners: validate with a thickness analysis tool before every print.
Related terms: Shell / Hollow, Fillet, Chamfer, Draft Angle
| Field | 3D design, 3D printing, engineering |
|---|---|
| Also called | shell thickness, minimum wall, wall width |
Engineer, author of The Big Book of 3D Printing and additive manufacturing expert