How to Convert STL to STEP Format: A Comprehensive Guide

Discover how to convert STL files to STEP format for CNC machining, ensuring precise and efficient manufacturing processes.

Table of Contents

What is STL?

edit stl file

Stereolithography (STL) is a common file format attributed to the representation of surface geometry in three dimensions. Primarily, the use of STL files is for the purpose of 3D printing which has wide applications in CAD and computer graphics. STL files define not only three-dimensional objects but also collections of triangular facets each of which is a set of three vertices and a normal vector. To achieve this compact representation, STL files are simple to create, parse, and edit.

Nonetheless, the simplicity of the STL format is accompanied by its limitations. There is a loss in features such as color, texture, or peering into the depth of 3D models when STL files are used. Therefore, they are not an appropriate type of file for the description of complex three-dimensional models.

What is STEP?

STEP (Standard for the Exchange of Product Model data is an ISO 10303 international standard that is used for the exchange of 3D product data between CAD software. It is one of many standards in the ISO series. These standards are developed by the International Organization for Standardization (ISO) to allow engineers and designers to get different CAD systems to work with each other. So they can share and use product model data when it is designed in one software in a different software environment.

STEP files, having the flexibility to support complex geometric structures, assemblies, and attribute information, are considered more inclusive than those designed to take only some detailed information. They may provide geometric shapes of for example a product, material properties, assembly relations and manufacturing information, etc. from which they can be exchanged and shown across different file formats. In the words of the format, the exchange of information between CAD software that is developed by different vendors will be easier. Besides this, there will be avoidance of compatibility issues between certain software formats that will improve the efficiency of engineering design and manufacturing.

Why do you need to convert STL to STEP?

It is very important to convert STL files to STEP since they lack critical assembly information and attributes. This can be done by using converter software such as SketchUp and Onshape that will modify the STL into a well-detailed STEP format, which is suitable for complicated engineering applications.

The use of STEP results in improved data exchange, processing collaboration efforts, engineering analysis, and production processes. Moreover, it is possible to edit the converted files on software like Onshape for customization purposes.

The overall result is an improved efficiency and accuracy that enhances effective communication in different software environments thus leading to smooth integration within the designing process.

How to convert stl to step?

  • CAD Software: Utilize CAD software such as SolidWorks or AutoCAD. These programs allow you to directly import the STL file and then save or export it in STEP format.
  • Conversion Tools: Explore specialized conversion tools designed for file format conversions. These tools are capable of converting STL files to STEP format efficiently.
  • Manual Reconstruction: In certain cases, manual remodeling of the STL model into STEP format may be necessary. This involves recreating the model in a CAD program to match the original STL geometry.

The process of the step of converting stl to step

1. Acquire a Conversion Tool

Choose a qualified software or tool that satisfies the requirement to STL to STEP conversion.

2. Import Your STL File

Load your STL file by opening it on the specified conversion software interface.

3. Mesh Repair

Review the imported STL file for any errors or faults existing in its mesh. Through the mesh user interface, the system will use the functionality to repair the identified problems.

4. Mesh to Shape Conversion

Employ the conversion tool in your task and replace the patched-up mesh with the geometric shapes or surfaces and the model’s authenticity will not be compromised.

5. Shape to Solid Conversion

Convert the geometric shapes or surfaces into solid elements overall inside the software and complete the closed bodies to be ready for the next process.

6. Confirm Units and Precision

Make sure all unit and decimal points were accurately shown during the conversion process and have maintained the correct level of precision that you need for your project. Adjust settings to those desirable by pursuing necessary settings within the software.

7. Dimension and Proportion Verification

Compare the dimensions and proportions of the molding model with the specification of the original design to avoid inaccuracies.

8. Validate Conversion Settings

Double-check everything within the software like file formats, units, and precision settings to be sure that the methods used are well-matched and accurate.

9. Entity Attribute Confirmation

Verify that what are called attributes ( e.g. materials, color) of the STEP file objects accord with original design and remain project requirements.

10. Export to STEP Format

Complete the conversion process by exporting the solid model in the STEP file, which is used for saving the work. Start saving the file to the place where you can use it or share it further.

The Software for STL to STEP conversion

STL to STEP program
STL to STEP program
  • FreeCAD: an open-source CAD software that can import STL files and export them as STEP files.
  • Open CASCADE Technology (OCCT): a CAD development framework that provides tools for STL to STEP conversion.
  • Autodesk Fusion 360: a powerful CAD/CAM/CAE tool that can import STL files and convert them to STEP format.
  • SolidWorks: a professional CAD software that can import STL files and convert them to STEP files.
  • Rhino: Rhino is a professional 3D modeling software that can import STL files and export them in STEP format.
  • CATIA: CATIA is a widely used CAD software for engineering design and manufacturing, capable of handling STL files and converting them to STEP format.

Convert STL to STEP for free and online

Online STL to STEP Convert
Online STL to STEP Convert
  • FreeCAD: With FreeCAD, you will easily be able to load. STL files and freely export. STEP files. download and install FreeCAD software, and open the STL file with the step option of exporting.
  • Anyconv Web: Internet FreeCAD gives you the chance to convert STL data to STEP model in your browser. Go to to STL file-to-step format online using the site.
  • OnlineCADConverter: Apart from this, the other online tool for converting STL files into STEPS format is also available. Please visit to convert your STL file to the STEP format online.


Converting STL to STEP enhances data exchange, collaboration, and customization in CAD environments, improving efficiency and accuracy in design and production processes.

Let us help you simplify your CNC machining process. Contact us today to convert your STL files to STEP format and elevate your manufacturing capabilities.


On-demand CNC Machining prototyping and parts with Custom Finishes and low volume manufacturing.

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