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Convert STEP to 3MF Online: STP to Mesh Geometry

Convert STEP/STP models to 3MF mesh geometry. Print profiles, materials and manufacturing instructions are not created.

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Capabilities and limits

  • Convert STEP/STP models to 3MF mesh geometry. Print profiles, materials and manufacturing instructions are not created.
  • Conversion preserves supported geometry rather than native parametric feature history; verify output units, completeness and geometry.
  • Files are uploaded for server processing; support depends on format, version and geometry.
  • Viewing and measuring do not require an account. Free conversion points are valid for 90 days. Sign in to convert, save files across devices or create share links.
On this page

Convert a STEP or STP model to 3MF when you need mesh geometry in a 3MF package. The output does not include print settings or manufacturing instructions.

Check the STEP geometry before export

Confirm units and that the bodies you intend to print or view are present. 3MF will carry the tessellated shape, not the original CAD construction.

Convert STEP to 3MF geometry

Choose 3MF and download the file. The conversion writes core mesh geometry. It does not write printer profiles, slice settings or manufacturing instructions.

Treat the result as a mesh

Declared 3MF units are converted to millimetres when CADProps measures the file. Dimensions and area are approximate. Volume requires a closed, consistent mesh.

Input formats: STEP / STP

Points: viewing and measuring are free. A new account gets 3 free conversion points; free points are valid for 90 days. One point converts one file to every output format for 30 days, and a failed or incomplete conversion uses none. See pricing.

Open this tool

General steps for uploading, viewing, sectioning, measuring, converting and exporting are explained once in How it works. This page covers what is specific to this file type.

Real CADProps screenshots

The screenshots show the English interface. Captions and instructions describe the same operations.

Convert CAD files — block.step
Convert CAD files — block.step

Sample source and verification

Properties — step-to-3mf.3mf · 40 × 30 × 20 mm · 24,000 mm³ · 5,200 mm²
Properties — step-to-3mf.3mf · 40 × 30 × 20 mm · 24,000 mm³ · 5,200 mm²

When a result needs another check

Viewing can start without an account. Conversion, account storage and share creation require signing in. Temporary files expire after the displayed retention period. Read the privacy statement for server processing and deletion, and the accuracy notes before using numerical results. Do not assume that hiding a part, clipping it or exploding an assembly changes the exported source geometry.

When a result needs another check · Input formats

Continue with a related task

Original article: CADProps · https://www.cadprops.com/tools/step-to-3mf/

A reproducible example

Convert the generated 20 × 30 × 40 mm STEP block to 3MF. Inspect the mesh orientation and compare its bounding box with the source before slicing.

Repository-generated samples are synthetic test models. Verify your own model's units and geometry before using results.

Supported formats
All formats and limits →

Questions about this task

Can I convert STEP to 3MF online?

Yes. Upload a STEP or STP file, choose 3MF and download the mesh package.

Does the 3MF file include print settings?

No. The conversion contains geometry only. Printer profiles and manufacturing instructions are not created.

Is 3MF volume the same as the STEP solid volume?

No. 3MF measurements are mesh approximations. A closed STEP solid can have a precise volume; the 3MF result depends on the triangle mesh.

Do I need an account to convert files?

View and measure without an account. Register or sign in to convert, save files and create share links. Recipients can view shared models without an account.

Related reading

Checks that help with this file.

All guides →
Opening files

STEP File (.step, .stp): What It Is and How to Open It

A STEP file is a neutral ISO 10303 CAD model saved as plain text. See what it contains, how to open a .step or .stp file online, and what to check first.

Read the guide →File formats

3MF vs STL: Units, Multiple Parts and Mesh Handoff

Compare 3MF and STL for mesh exchange, including declared units, packaging, multiple objects, metadata and what CADProps can actually inspect from each format.

Read the guide →Conversion

STL Export Settings: Mesh Resolution, Units and Scale

Choose tessellation settings for the receiving task and verify curved features, thin regions and units after exporting.

Read the guide →Conversion

CAD File Conversion Checklist: Units, Solids & Accuracy

Reopen the output, verify scope and units, inspect critical geometry, and include a short record of what was and was not checked.

Read the guide →