What is a step file?

Most of our 3D CAD libraries contain 3D models in the step file format. It therefore seems a good idea to explain what the step file format is, and what the advantages and disadvantages of this file type are.

Step file imported in Autodesk Inventor

What is a step (.stp) file and what can you do with it?
Step (.stp) is a file format that is designed to share three dimensional models between different CAD systems. STEP means: STandard for the Exchange of Product model data. 

In fact a step file is a text file, containing all the 3D data in ASCI text code. The way of storing the data is in accordance with the standards, defined in ISO 10303-21 : Clear Text Encoding of the Exchange Structure.

Can my 3D modeling software import step files?
All the major solid modeling programs recognize the step file format and are able to use these models in the assembly of a project.

Some programs that can open step files are:

• Autodesk Inventor
• Autodesk Fusion 360
• Autodesk Showcase
• Dassault Solidworks
• Dassault Catia
• Ismi Turbocad
• Siemens Solid edge
• Freecad
  
  

Advantages of the step file format:

1. Files in step file format are approximately the same size as the source files, but a very good thing is that they compress much better. The size of a compressed file step is about 20% of a compressed version of the source file. This makes the file type is therefore ideal to be shared over the internet.
   
   
2. Another very positive point to this "intermediate file type" is that it allows a downward compatibilty. For example: a file created with Autodesk Inventor 2016 can still be used in Autodesk Inventor 2015, or Inventor 2014, by using the step file format as intermediate link.
   
   
3. There is no loss of quality in comparison with the source files in terms of detail and dimensional stability.
   
   
4. It is a robust, reliable and easy to use file type. Our experience is that step is much more reliable than other exchange formats, like the IGES or SAT file format.
   
   
5. You can always directly use 3D CAD libraries in step file format. That means: without converting them to your native program files first.
   
   

Disadvantages of the step file format:

1. The lack of opportunities to change the model. "What you see is what you get". For many 3D models that's no problem at all, simply because they are already complete and high detailed (like the Wyalo 3D models for example).
   
   
2. Step files cannot contain parametric intelligence and feature history. Therefore is't very important to use well thought out filenames, because this is the only input data property all 3D programs recognize for use in part lists for example.

Conclusion:
For making 3D CAD models accessible to multiple types of CAD 3D programs, it is necessary to use an intermediate file type. 
The step file format is a good choice if you don't have to make changes in it's geometry.

The Wyalo step files:
Our step format files always have well thought filenames and do not have parametric data needed, simply because are 3d models are already complete, high detailed  and dimensioned according to the international standards.
We only use the benefits and we bypass the disadvantages.

If you want to be sure your 3D cad system can handle step files, download one or more free 3D CAD models in the tep file format here.