# When 3D printing is the right process, and when it is not

> FDM 3D printing has clear strengths and limitations. An honest guide to whether it suits your part.

Canonical: https://printimir.ch/en/guides/when-3d-printing-is-right

## When 3D printing is the right process, and when it is not

FDM builds a plastic part layer by layer. It is ideal for one-off parts and small batches, but has limits in strength, heat resistance and accuracy. Here is what to consider.

### Strengths

- One-off parts and small quantities without tooling costs
- Complex geometries that are difficult to manufacture otherwise
- Fast iteration for prototypes
- Replacement parts that are no longer available

### Strength limitations

A printed part is weaker between layers than within a layer. Tension across the layer direction can cause it to break along a layer line. Print orientation, material and infill determine the load the result can bear. For structural or safety-critical parts, assess suitability based on your design.

### Heat limitations

PLA begins to soften at roughly 50 to 60 degrees Celsius, while PETG withstands somewhat more. Parts in direct sunlight, an engine compartment or beside a heater require care. Tell us the operating temperature and we will assess suitability.

### Accuracy limitations

Our dimensional tolerance is plus or minus 0.3 mm or plus or minus 0.5%, whichever is greater. Allow clearance for fits that must be accurate to a tenth of a millimetre, or discuss the part with us first.

### Unsuitable applications

Our prints are not intended for prolonged food contact or medical applications. The layer structure cannot be cleaned reliably enough for those uses.

### Frequently asked questions

#### Is FDM suitable for functional prototypes?

Yes, for many form, fit and basic function tests. Suitability depends on the intended use.

#### How large can my part be?

Up to 256 mm along each edge as one piece. We can split and bond larger parts.

#### Can you tell me whether my part will hold?

We can assess the material and expected load, but this is not a certified strength guarantee.

### Read next

[3D-printed prototypes](https://printimir.ch/en/3d-printed-prototypes) · [Materials and process limitations](https://printimir.ch/en/materials) · [Request a project](https://printimir.ch/en/3d-modeling/request) · [All guides](https://printimir.ch/en/guides)

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[Upload model](https://printimir.ch/en/3d-printing/upload-model) · [Request a project](https://printimir.ch/en/3d-modeling/request)