What is a CAD File Format? How to Open, Create, Edit, and Convert it

What are CAD files?

CAD means Computer-Aided Design, which is design software containing information about the project. CAD files are digital files that house 2D and 3D models of physical objects. They include material properties, manufacturing data, geometric data, and other process or product information. 

CAD files are used mainly by digital artists, scientists, manufacturers, engineers, and designers to create architectural plans or models. 3D CAD files represent the assemblies or parts, while 2D files are the drawings. 

CAD files exhibit the following features or properties:

1. Geometric Representation: CAD files include the boundary and polygonal representations of 2D and 3D information, which define the precise bounds and topological entities that serve as the basis of B-Rep bodies and B-twin Rep. 
2. Topology: Topology plays a vital role in B-Rep representations, including body types such as acorn shapes, sheets, wireframes, and solids and elements like faces, edges, and shells.
3. Product Design: The product structure consists of groupings of interlinked elements referred to as single objects and assemblies arranged in hierarchies known as components. 
4. Metadata: CAD files have metadata, including user-defined properties, object IDs and names, manufacturing information, validation and product attributes, layers, structure, typography, and geometry. 
5. Visual Representation of Qualities: CAD files denote aesthetic features such as light sources, textures, line styles, materials, and colors. 

Types of CAD Files

CAD files are of two types: Native and neutral. The neutral CAD files are interoperable between various CAD software, allowing data importation and exportation by different programs or applications. On the other hand, the Native CAD files are designed for use specifically with the proprietary CAD software.

Native CAD Files 

Full Name	Extension	Dimension	Definition	Year	Software	File Viewer
Creo	.asm or .prt	3D	MBD	2010	CAD	SolidWorks
AutoDesk Inventor	.ipt or .Iam	3D	MBD	1999	AutoDesk CAD	Autodesk
Computer-Aided Three-dimensional Interactive Application (CATIA)	.CATProduct, .CATPart	3D	MBD	1977	CATIA/CAD	CATIA
AutoCAD Drawing (DWG)	.dwg	3D	MBD	1982	AutoCAD	AutoCAD
AutoCAD Drawing Exchange Format (DXF)	.DXF	2D & 3D	MBD	1982	AutoCAD	AutoCAD
SolidWorks	.sldasm or .sldprt	2d & 3D	MBD	1995	SolidWorks CAD software	SolidWorks CAD software
Next Generation Unigraphics (NX-Unigraphics)	.prt	3D	MBD	1973	CAD Software	SolidWorks
Solid Edge	.Par, .ASM	3D	MBD	1995	CAD Software	SolidWorks

Neutral CAD Files 

Full Name	Extension	Dimension	Definition	Year	Software	File Viewer
Three Dimension Portable Document Format (3D PDF)	.pdf	3D	Non-MBD	2004	CAD software	Adobe Reader
Quality Information Framework (QIF)	.QIF		MBD	2013	CAD software
Stereolithography (STL)	.stl	3D	NON-MBD	1987	CAD software	CATIA
STEP	.stp, .step	3D	MBD	1994	CAD software	CAD software
Initial Graphics Exchange Specification (IGES)	.igs, .iges	2D and 3D	NON-MBD	1980	CAD software	CATIA, Solid Edge,
Jupiter Tessellation (JT)	.JT	3D	MBD	2007	CAD software	CATIA
Standard ACIS Text  (ACIS-SAT)	.SAT	3D	NON-MBD	1989	CAD Software	Autodesk AutoCAD/SolidWorks
PARASOLID-XT	.X_T, .xmt_txt	3D	NON-MBD	1980s	CAD Software	SolidEdge

What are CAD Files used for? 

CAD files are used exclusively with the CAD software in industries like Energy, High-Tech, Retail, Consumer Goods, Healthcare, Industrial Equipment, Construction, Marine, and Automotive to improve product manufacturing, documentation, quality, and productivity. CAD files are critical in:

• The analysis and optimization of product design.
• Creating digital content and prototyping. 

Pros and Cons of CAD Files 

CAD files are widely used by design experts who need precision in technical drawings. However, CAD files are hardly opened using technical drawing programs since they require a blend of mathematical formulas and tools to produce precise designs and to get started, resulting in the associated benefits and demerits.

Advantages of CAD Files

1. Easily edited: CAD files allow users to alter designs because they are used with CAD software that easily fixes any errors and modifies the drawings.
2. Decrease design effort: When designing different models using CAD files, less effort is required because the CAD software automates most CAD file-related tasks.
3. Easily shared or transferred: The CAD tools make it easier to save and store CAD files so that they can be used and shared again and again without any undesirable hassles.
4. Improved accuracy: CAD files are used to attain optimal drawing because the CAD software used with such files can gauge the accuracy level of the designs.

Disadvantages of CAD Files

1. Corrupted or lost Files: Design works are prone to deletion or can be lost when computers suddenly break down.
2. Hacking and virus threats: CAD files are prone to viruses or can be easily hacked.
3. Training: CAD files are exclusive to CAD software, so learning how to operate them takes time. 
4. Software Update: CAD files need to be regularly updated. 

How to Open or View CAD Files 

To open or view CAD files, use software or programs such as:

• AutoCAD mobile application
• AutoCAD mobile app or web app
•  Autodesk DWG TrueView
• Autodesk AutoCAD
• DWG FastView
• IMSI TurboCAD
• DWG DXF Sharp Viewer
• IntelliCAD
• Graphisoft ArchiCAD
• ProgeCAD iCADMac
• CorelCAD
• CADSoftTools ABViewer.

For instance, to open or view a CAD file using AutoCAD, follow the below steps:

1. Download and install Autodesk AutoCAD to your PC
2. Launch the program
3. Go to File > Open > Browse.
4. Next to the File Name box, click the All-Visio Files drop-down> select AutoCAD Drawing.
5. Find your CAD file > double-click it. 

How to Open CAD Files Online 

To open CAD files online, use online CAD file viewers such as:

• DWG Viewer
• DWGSee
• DWG FastView
• Autodesk Viewer
• AutoCAD Web
• ShareCAD
• AutoCAD Web

For example, to open a CAD file online using AutoCAD Viewer, follow the below steps:

1. Register for the software/Sign up
2. Click on the "Upload" icon
3. Navigate to locate your CAD file, e.g., from Cloud, Google Drive, PC, etc
4. Allow the program to run, upload, and open the CAD file

How to Make or Edit CAD Files  

You can make or edit different CAD files in AutoCAD. CAD files that can be created and edited using AutoCAD include DXF, X3D, or DWG. While each CAD file can be created and edited differently, follow the steps below to create a DWG file in AutoCAD:

1. Download and install AutoCAD on your PC

2. Launch AutoCAD 

3. Go to Start > New (use the drop-down icon next to 'New' to browse and select a template).

Alternatively, you can export other file formats to make a DWG file

4. Go to File > Export > DWG Formats 

5. Select Setup > Views and sheets to export > click 'Next.' 

A dialogue box opens.

6. Select a location to save the DWG file to > choose the AutoCAD version for the file.

7. Amend any other settings as required > click 'OK.'

To edit a DWG file in AutoCAD, follow the steps below: 

1. Click the Files tool.
2. Navigate to find your DWG file (ensure the pop-up dialog boxes are enabled)
3. Click Open (You can now view and edit the DWG file based on the permissions).
4. Click Save to save the edited DWG file. 

How to Reduce CAD File Size 

Reduce CAD file sizes using software such as Scan2CAD, AutoCAD, or GstarCAD. The tools optimize CAD file sizes by eliminating unnecessary layers, blocks, or vector data. To reduce a CAD file size in AutoCAD, do the following:

1. Download and install AutoCAD
2. Open the program 
3. Type SCALE (in the AutoCAD command) > Specify a number between 0 and 1
4. Hit Enter (It scales down the size of the objects by the chosen factor).

Alternatively, you can scale down the entire CAD drawing by following these steps:

1. Launch the AutoCAD program
2. Select "Custom" to open up the 'Edit Drawing Scales.' 
3. Add your custom drawing scales to the list 
4. Click OK.

How to Recover a CAD File 

To recover a corrupted or damaged CAD file, use the online recovery toolbox or AutoCAD built-in feature. 

1. How one can recover a CAD file online 

You can recover a corrupted or damaged CAD file online using the 'Repair Toolbox.' Follow these steps: 

1. Go to repairtoolbox.com
2. Select the corrupted or damaged CAD file
3. Click the Next button
4. When the File recovery online process is successful,  the restored CAD file and a preview of the restored CAD file will appear
5. Pay for the AutoCAD file recovery online service
6. Download and Save the recovered AutoCAD CAD file 

2. How to recover a CAD file in AutoCAD

The following steps explain how you can recover a damaged or corrupted CAD file:

1. Download and install AutoCAD on your computer
2. Click the Application button > Drawing Utilities > Recover. 
3. Under the Select File dialog box, browse to find and choose the CAD file to recover
4. Click Open. When AutoCAD prompts you to open the CAD as read-only, click Yes.
5. Review the audit details in the Open Drawing - Damaged File message box and click Close.

How to Convert CAD Files with Convertjack 

You can convert CAD files to DAE, 3MF, STP, DWFX, STP, CGM, OBJ, EMZ, EMF, WMZ, and 3DS using Convertjack. Our CAD file converter allows users to easily convert their CAD files to other file formats in three steps:

1. Upload the CAD file
2. Choose the file format the CAD is to be converted to
3. Click Convert and download the converted file

Note: You can also do batch conversion with multiple CAD files.

CAD Files Frequently Asked Questions (FAQs)

1 Which is the most common CAD file format?

The most common CAD file format is DWG. 

2 How do you make a CAD file for 3D printing?

To make a CAD file for 3D printing, do the following:

1. Choose the best AutoCAD Software, such as Fusion 360 or TinkerCAD
2. Download, install, and launch the program
3. Start with the Design Concept
4. Learn the CAD software (commands, tools, and user interface)
5. Create a 2D sketch (Use arc, lines, and other drawing tools)
6. Resolve or Extrude to give your 2D drawing depth and turn it into 3D
7. Add Features and Details (Use Additional Tools to add dimensions, features, and details to the 3D)
8. Apply Materials Textures and Materials
9. Check for Errors
10. Rendering (Export the 3D model to a dedicated rendering software)
11. Save and Export (Save the 3D model in a CAD program’s native file format)
12. Iterate, Refine, and Print

3 What Programs can open CAD files?

Programs that can open CAD files are Autodesk Viewer, AutoCAD web or mobile applications, IntelliCAD, GraphiSoft ArchiCAD, ProgeCAD iCADMac, CorelCAD, CADSoftTools ABViewer, DWGSee, and DWG FastView.

4 What is the file extension for CAD drawings?

The common file extensions for CAD drawings are .DWG and .DXF. These formats are widely used for storing and sharing CAD data across various design and drafting applications.

5 How to save CAD files to older versions?

To save CAD files to older versions in AutoCAD, follow the steps below: 

1. Open AutoCAD.
2. Go to the Quick Access Toolbar, click the Save As button.
3. In the Save Drawing As dialog box, change the file name to avoid overwriting the original.
4. In the Files of Type drop-down menu, select the desired older version of the DWG or DXF format.
5. Click Save to save the file in the chosen older version.