3D CAD Translation: Importing & Exporting The Right Format

17 Jan 2020 by Jimmy Nguyen


With over dozens of CAD software and an equal amount of CAD file types, importing & exporting the right format helps tremendously when it comes to data integrity and minimizing errors & rework.

This is especially true for downstream applications from design engineering to manufacturing.

As digital transformation sweeps across manufacturers, suppliers, and factories, MBD (model-based definition) CAD is slowly but surely becoming a future practice of MCAD as the next generation of engineers work directly in the 3D model to add GD&T, general notes, BOM, and other 3D annotations.

With that in mind, we look at the best CAD formats that are “translation-friendly,” especially when it comes to model-based definition or verifying CAD derivatives for requirements like Boeing DPD.

Major CAD Software Developer Major Import/ Export CAD Files
Creo PTC ACIS, DXF/DWG, IGES, JT, NX (import only), Parasolid, PDF, SolidEdge (import only), SolidWorks (import only), and STEP.
SolidWorks Dassault Systemes ACIS, CATIA V5, DXF/DWG, IGES, Parasolid, PDF (export only), STEP, and STL.
Inventor Autodesk


CAD Standards 

It's important to note that we're recommending CAD files that are standards. Standards have a known structure, are documented, and governed by a national or international standards body like the International Standards Organization (ISO) or American Society of Mechanical Engineers (ASME).

Therefore they provide a common, well-defined language that two software systems can use to communicate with each other.

MBD Neutral CAD File Formats 

MBD CAD are 3D CAD files with semantic PMI embedded within the model. This allows for downstream use from a single source of truth: the CAD model itself. STEP & QIF are the two most mature formats and are standards, which ensures a way to import/export data consistently between CAD systems.

STEP (File Extension: .STEP, .STP)

STEP (Standard for the Exchange of Product model data) files are ubiquitous across multiple CAD software and used across multiple industries. 

It is interoperable between different systems including CAM (computer-aided manufacturing), CAI (computer-aided inspection), and CAE (computer-aided engineering).

In regards to mechanical CAD, there are three major STEP file formats:

  1. STEP AP203: Defines geometry, topology, and configuration management data of solid models for mechanical parts & assemblies. 
  2. STEP AP214: Includes STEP AP203 features along with colors, layers, GD&T, and design intent.
  3. STEP AP242: Merges both STEP 203 & STEP 214 to introduce model-based definition (MBD) engineering.

For companies or departments venturing into the digital transformation process, using the STEP AP242 file is a solid beginning point, because it’s the only MBD-ready of the three STEP formats.

QIF (File Extension: .QIF)


QIF (Quality Information Framework) files are made for the 21st century engineer.

It’s a newer CAD format that optimizes for semantic PMI, which allows for human & machine-readable CAD. This leads to true MBD processes for automation, interoperability, and traceability from design to manufacturing.

It’s also highly valued in Metrology and Quality departments, and gaining strong support in the model-based enterprise community.

Interested in MBD (model-based definition) CAD translator?

Learn More: MBDVidia

Capvidia leads the field in MBD CAD translation & validation. Talk to our team today.

Non-MBD Neutral CAD File Formats

Neutral CAD files are intermediary files used to translate data between CAD systems. They work extremely well for visual representation or wireframe geometry. IGES and STL are also standards which ensures smooth import/export between CAD systems.

IGES (File Extension: .IGS, .IGES)

IGES (Initial Graphics Exchange Specification) files are the first, and therefore, oldest neutral CAD file. Although technically superseded by STEP and QIF, it’s been around so long that it has widespread adoption from many CAD software.

It supports surface geometry and solids, although it’ll be more prone to errors such as gaps between surfaces, missing faces, wrong orientation, and lost of history depending on the export options.

Stereolithography Files (File Extension: .STL)

STL files are mesh models and are about surface geometry and shapes. However, it doesn’t include colors, textures, and other model attributes.

So what is it good for? 

Rapid prototyping, some CAM software, and especially 3D printing where it’s a common file.

Geometric Modeling Kernels

You can take advantage that some software tools share the same underlying geometric modeling kernels which means you avoid unnecessary translation of data.
If you need to share data that use the same kernel, then you can simply keep the data in that kernel's file format, and avoid a data translation!

ACIS and PARASOLID are the two most used kernels.  However, they are not standards.

ACIS (File Extension: .SAT, .SAB)

ACIS is maintained by Dassault Systemes and used in many CAD, CAM, CAE, and CMM software.

Companies and products using the ACIS kernel: AutoDesk, BricsCAD, Cimatron, Colbat, IronCAD, Mitutoyo, SpaceClaim, ZEISS CALYPSO, and others.

PARASOLID (File Extension: .X_T, .X_B)

Parasolid is maintained by Siemens and used in many CAD, CAM, and CAE software.

Companies and products using the Parasolid kernel: Abaqus FEA, ADINA, ANSYS, MasterCAM, NX, Onshape, SimScale, SolidWorks, SolidEdge, T-Flex, and others.

Final Thoughts:

Capvidia is proponent of MBD data, so we’d recommend exporting into STEP and QIF as a best practice, especially if your department or company is exploring digital transformation or model-based enterprise.

To share 3D MBD,  these are the recommended ways to share the data:
  1. Native CAD (e.g. Creo to Creo file): This is the most reliable way to maintain the complete model definition, including MBD. But this requires the receiving end has the same CAD system and the intellectual property can be shared. Also, staying within the walls of one proprietary CAD system can seriously limit your options as far as CAM, CAI, and other downstream software.
  2. Geometric modeling kernels  (Parsolid, ACIS): This is also a very reliable way to exchange data between CAD systems with the same geometric kernel. But this is limited to geometry and may not include any MBD.
  3. Neutral CAD file formats (STEP AP 242, QIF) : This standards-based method supports the translation of geometry and MBD between any CAD system.

How can we help? We're more than software and processes. It's about people.

Contact Us

Capvidia is a leader in CAD translation & validation, especially pertaining to digital transformation and the MBD journey. Have questions? Talk to our team today.

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