3D Printing Tolerances
FDM accuracy: The accuracy of a desktop FDM 3D printer is around ± 0.5 mm. The accuracy of an industrial FDM printer is around ± 0.2 mm.
Resin: The accuracy of a desktop resin 3D printer is around ± 0.1 mm. The accuracy of a professional resin 3D printer is around ± 0.01 mm.
Powder Bed: The accuracy of a powder bed fusion 3D printer is around ± 0.1 mm.

Article



Tolerances
Desired FitClearance Gap (in)Clearance Gap (mm)
Press FitLine to LineLine to Line
Tight Fit0.0050.127
Normal Fit0.0100.254
Loose FitThe accuracy of a desktop FDM 3D printer is around ± 0.5 mm. The accuracy of an industrial FDM printer is around ± 0.2 mm.0.0200.508
2. Minimum Wall Thickness (0.8 with .40mm nozzle  & Feature Size. The minimum wall thickness is directly related to your nozzle diameter. On GRR machines, the default nozzle size is 0.040 mm nozzle which corresponds to the minimum wall thickness. A “bad wall” is one that only lays down one bead of plastic. The “minimum stable wall” will lay down two beads and a “better wall” will put down more than two beads.  Bearing this in mind, the minimum feature size is also driven by your nozzle diameter. It must be at least two times the nozzle size.

So again, on GRR machines, with a default nozzle size of 0.40 mm, the desired minimum feature size is going to be 0.8 mm (0.031”).