CAD File Extensions

As a company that specializes in CAD Translation, we often get questions about a wide range of CAD file extensions; to make this easier on our customers, we’ve compiled a list of the most common Brep and Visrep formats.

Please note: This is a list of all known CAD File Extensions, not a list of formats that TransMagic can Read and Write. For a list of formats supported by TransMagic products, please visit our CAD Formats page.

Brep vs Visrep

Brep stands for Boundary Representation, which is a true CAD format. Visrep stands for Visual Representation, which is a polygonal or tesellated format. We are including both Brep and Visrep formats in this listing since there is often confusion as to which is which. Where possible, additional notes are provided for each CAD file extension.

Find out more about Brep vs Visrep here.

Software Extensions Brep or Visrep Notes
3D PDF .PDF Visrep 3D PDF is a great format for sharing geometry with those who do not have access to CAD systems or CAD viewers; all that’s required is the Adobe Reader, which is already on almost all PCs.
3D XML .3DXML Visrep 3D XML is a visualization format developed by Dassault Systemes.
3DS Max Files .3DS, .MAX Visrep .3DS files contain mesh or nurbs information; .MAX files contain all scene information, including mesh data.
ACIS Model & Assembly Files .SAT, .ASAT, .SAB, .ASAB Brep ACIS is a geometric modeling kernel used in many CAD applications. .SAT and .SAB files are part files, .ASAT and .ASAB files are assembly files. Files that end with B are binary.
Alias Model file .WIRE Visrep
AutoCAD Drawing Files .DWG, .DXF Brep and Visrep .DWG files are binary, .DXF files are ASCII. Both formats can contain both Brep and Visrep geometry.
Autodesk Filmbox Format .FBX Visrep Primarily used for exporting mesh, material and animation data to game engines.
CADKEY File .PRT, .CKD Brep CADKEY is now known as KeyCreator.
CATIA V4 Part & Assembly Files .MODEL Brep .MODEL files can represent both parts and assemblies.
CATIA V5 Parts and Assemblies .CATPart, .CATProduct Brep
CATIA V5 Graphical Representation File .CGR Visrep
CATIA V6 Part and Assembly Files .CATPart & .CATProduct Brep File format is similar to V5 files.
Collada Object Format .DAE Visrep
Creo Part and Assembly Files .DRW, .PRT, .ASM Brep .DRW are drawing files, .PRT are part files, and .ASM files are assembly files. Creo was formerly known as Pro/Engineer.
Fusion 360 Files .F3Z, .F3D, .CAM360 Brep .F3Z files are archive files, .F3D are part files, and .CAM360 are toolpath archive files.
Generic CADD Files .CMP, .GCD Brep .CMP files are component files, .GCD are drawing files.
Geomagic GeomView Design File .WRP
Gerber Printed Circuit Board File .GBX
HOOPS Metafile Format File .HMF Visrep
HOOPS Stream Format File .HSF Visrep
IGES .IGS, .IGES Brep IGES files are predominately surface files, though the definition does allow for solid models. Read more about IGES, learn  why to avoid IGES, and alternatives to IGES.
Inventor .IPT, .IAM Brep .IPT files are part files, .IAM files are assembly files.
IronCAD .ICS Brep
JT .JT Both JT, created by Siemens / NX, is unusual in that it can contain both Brep and Visrep content. JT is also compressed about 8:1, so it is a good visualization format for large assemblies.
KeyCreator Part & Assembly Files .CKD, CDL Brep KeyCreator was formerly CADKey; .CKD files are for parts and assemblies, .CDL files are for Wireframe Design files.
Kubotek Design Container File .CKD Brep
Lightwave Object File .LWO Visrep
Microstation Design Files .DGN Brep
Modo Scene Format .LXO Visrep
Navisworks Files .NWC, .NWD, .NWF .NWC files are cache files, .NWD are documents, .NWF are file sets.
NX Part and Assembly Files .PRT Brep NX was formerly Unigraphics; one confusing aspect to NX .PRT files is that the same extension is used for both parts and assemblies.
Parasolid Model File .X_T, .X_B Brep Parasolid is the geometric modeling kernel used for SOLIDWORKS, Solid Edge, and many other CAD solutions; read more about Parasolid here.
POD .POD Visrep
PLY .PLY Visrep
Pro/Engineer Granite File .G Brep Granite is the geometric modeling kernel behind all Pro/E and Creo products.
Pro/Engineer Part and Assembly Files .PRT, .ASM Brep Pro/Engineer is now known as Creo
Rhino 3D Model File .3DM Brep Rhino is primarily a freeform NURBS surface modeler specializing in complex surface creation.
SDRC .PRT, .ASM Brep SDRC was purchased by EDS in 2001, and then by Siemens in 2007, and is no longer in existence as a CAD solution. Since version 11, I-DEAS was able to export parts and assemblies as Parasolid files to provide interoperability with NX.
Sketchup .SKP Visrep
SMlib .SMS, .IWB, IWP Brep SMlib is created by Solid Modeling Solutions; these files are geometric modeling kernels used in a range of CAD applications.
Solid Edge .PAR, .ASM, .PSM Brep .PAR files are part files, .ASM files are assembly files. Solid Edge is made by Siemens.
SOLIDWORKS Part & Assembly Files .SLDPRT, .SLDASM Brep .SLDPRT files are parts, .SLDASM files are assemblies. SOLIDWORKS is owned by Dassault.
STEP .STEP, .STP Brep STEP is the most popular neutral CAD format in the world today.
Stereolithography Files .STL Visrep .STL files are widely used for 3D printing.
Unigraphics Part & Assembly Files .PRT Brep Unigraphics is now known as NX; one confusing aspect to Unigraphics and NX .PRT files is that the same extension is used for both parts and assemblies.
Wavefront .OBJ Visrep .OBJ is widely used by modeling and animation solutions such as Maya and 3DS Max for transfering polygonal meshes.
ZBrush Files .ZBR, .ZPR Visrep ZBrush is a modeling and texturing application.
ZW3D .Z3 Brep ZW3D is made by ZWSoft.
VRML .WRL Visrep VRML stands for Virtual Reality Modeling Language.
WebGL .HTML Visrep WebGL stands for Web Graphics Library. This format allows viewing and rotating in any HTML5-compliant browser with no plugins needed, and is suitable for online parts libraries.

Try TransMagic’s CAD Translator

Many of these CAD file extensions can be read and written by TransMagic products; to see which ones, check out our CAD Formats page. Want to give TransMagic a try? Click here to try the free 7-day eval of TransMagic.

Related Articles

Brep vs Visrep Models – A comparison between Brep and Visrep models which looks at pros and cons of each.

The CAD Format Ladder Part 1 – A system to determine the best format for each situation.

The CAD Format Ladder Part 2 – Part 2, determining the best format for each situation.

What Format Do I Have Here? – Using the contents of the CAD file to determine the format and version.