How Accurate Is 3D Printing? What Tolerances Can I Expect?

1. Standard Tolerances by Technology

• FDM: ± 1 layer thickness for the first inch, ±0.002” per inch thereafter

• SLA: ±0.010” or ±0.002”/inch (whichever is greater)

• Industrial SLA — Same as SLA but for large-format parts up to 1000 x 1000 x 600mm

• MJF: ±0.010” for the first inch, ±0.002” per inch thereafter

• FGF — Very large parts up to 1800 x 1200 x 1100mm, 3mm min wall thickness

• MJF: ±0.012” for the first inch, plus 0.1% of nominal dimension

2. Minimum Wall Thickness

• FDM: 1.0–1.5mm recommended

• SLA: 0.8mm (standard), 0.8mm (high-res)

• MJF: 0.8mm recommended

• MJF: 0.8mm minimum

3. What Affects Accuracy?

Part Size — Larger parts have more room for thermal warping and shrinkage. A 1-inch part will be more accurate than a 12-inch part in absolute terms.

Material — Some materials shrink more during cooling. Nylon and ABS shrink more than PLA or resins.

Geometry — Flat surfaces and sharp corners are more prone to warping. Rounded features maintain accuracy better.

Orientation — Z-axis (vertical) resolution is determined by layer height. XY resolution is determined by the laser/nozzle precision.

4. Tips for Tight Tolerances

• Use SLA or for the tightest tolerances

• Specify critical dimensions in your order notes

• Add 0.2–0.3mm clearance for mating parts

• Request a test print before large orders

• Provide 2D drawings with GD&T callouts for critical features

5. What We Guarantee

Makelab inspects every part against standard tolerances for the chosen technology. If a dimension falls outside the standard tolerance range, we’ll reprint at no cost.

For tighter-than-standard tolerances, specify your requirements when ordering and we’ll confirm feasibility before production.