---
title: "3D Printing Tolerance Chart by Process | OpenSpindle"
description: "3D printing tolerance chart: typical dimensional accuracy and minimum wall thickness for FDM, SLA, SLS, MJF, and DMLS metal printing, hedged as typical."
canonical: https://openspindle.com/reference/3d-printing-tolerance-chart
---

# 3D Printing Tolerance Chart

Typical dimensional tolerance and minimum wall thickness by process, from FDM and resin SLA to SLS, MJF, and DMLS metal, so you can spec a printable part.

3D printing tolerances vary widely by process. Resin (SLA) and metal (DMLS) are the most accurate; FDM is the loosest; powder-bed SLS and MJF sit in the middle. Most services quote a floor tolerance plus a percentage of the nominal dimension, so accuracy degrades on larger parts. This chart gives typical dimensional tolerance and minimum wall thickness by process. Treat every value as a starting point: it depends on the specific printer, material, part geometry, orientation, and the service you use.

## Typical tolerance and minimum wall by process

Tolerances below are typical for a well-calibrated industrial machine. Many services state them as a floor for the first inch (about 25 mm) plus roughly 0.1% of the nominal dimension beyond that. Minimum wall is the thinnest reliable wall; thinner is sometimes possible on non-structural features.

| Process | Typical tolerance | Min wall thickness | Best for |
| --- | --- | --- | --- |
| FDM (filament) | +/- 0.2 to 0.5 mm (or +/- 0.5%) | ~1.0 to 1.2 mm | Cheap functional prototypes, jigs |
| SLA / DLP (resin) | +/- 0.1 to 0.2 mm | ~0.5 to 1.0 mm | Fine detail, smooth cosmetic parts |
| SLS (nylon powder) | +/- 0.3 mm (or +/- 0.3%) | ~0.7 to 1.0 mm | Durable functional nylon, no supports |
| MJF (nylon powder) | +/- 0.3 mm (or +/- 0.3%) | ~0.5 to 1.0 mm | Consistent end-use nylon at volume |
| DMLS / SLM (metal) | +/- 0.1 to 0.2 mm (plus ~0.1%) | ~0.4 to 1.0 mm | Metal prototypes and end-use parts |

*Typical values only. Actual accuracy depends on printer, material, orientation, part size, and service. Metal (DMLS) parts are usually finish-machined on critical features to reach tighter tolerances.*

## Why tolerance varies so much between processes

SLA cures liquid resin with a fine laser or projector, so it resolves the smallest features and holds the tightest tolerance. DMLS fuses metal powder with a laser and is accurate, but heat and residual stress mean critical faces are typically machined afterward. FDM extrudes molten filament bead by bead, so layer lines and shrink make it the loosest. SLS and MJF fuse whole beds of nylon powder without support structures, trading a little accuracy for strong, isotropic functional parts. Because most of these quote a floor plus a percentage, a 20 mm part holds far tighter than a 200 mm one.

## Design rules that protect tolerance

Orientation matters: the Z (build) axis is usually less accurate than X and Y, so place tight features in-plane. Add clearance to mating features rather than relying on nominal fit (roughly 0.1 to 0.2 mm for SLA, 0.2 to 0.4 mm for SLS and MJF, and 0.4 to 0.6 mm for FDM). Where a hole, thread, or mating face must be precise, print it undersize and ream, tap, or machine it, or move that part to CNC. Keep walls at or above the process minimum so features fully form and do not warp.

Values reflect common additive service specs and design guidance. Every number is process, printer, material, and service dependent; confirm the tolerance a service can hold on your geometry before release.

## On OpenSpindle

- [3D printing capability](https://openspindle.com/capabilities/3d-printing.md)
- [CNC machining tolerance chart](https://openspindle.com/reference/cnc-machining-tolerance-chart.md)

## Frequently asked questions

### How accurate is 3D printing?

It depends on the process. SLA resin and DMLS metal are the most accurate at about +/- 0.1 to 0.2 mm, SLS and MJF nylon hold about +/- 0.3 mm, and FDM is the loosest at roughly +/- 0.2 to 0.5 mm. Larger parts hold looser because most services add a percentage of the nominal dimension.

### Which 3D printing process has the tightest tolerance?

SLA (and DLP) resin printing resolves the finest features and holds the tightest dimensional tolerance, around +/- 0.1 to 0.2 mm on a calibrated machine. DMLS metal is comparable but is usually finish-machined on critical faces to hit tight tolerances reliably.

### What is the minimum wall thickness for 3D printing?

Typical minimums are about 0.5 to 1.0 mm for SLA, 0.7 to 1.0 mm for SLS, 0.5 to 1.0 mm for MJF, 1.0 to 1.2 mm for FDM, and roughly 0.4 to 1.0 mm for DMLS metal. Thinner walls can warp or fail to form, so stay at or above the process minimum on structural features.

### How do I hold a tight tolerance on a printed part?

Place critical features in the X-Y plane rather than the Z build direction, add clearance to mating features, and print precise holes or faces undersize so they can be reamed, tapped, or machined after printing. For truly tight features, a machined part is often the better choice.