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Why the .CAD File Format is Crucial in 3D Designs

Are you wondering what a CAD File is all about? Or Are you finding it difficult to open a CAD file. This article gives a detailed explanation on what CAD file does and how to open it. Keep reading to gain more knowledge.

What is a .CAD File?

Autodesk QuickCAD developed the CAD file. The term CAD means Computer Aided Design. A CAD file is a file format of an object produced and integrated by CAD software. Also, the CAD file comprises a blueprint or technical drawing of an item. The computer aided design and drafting (CADD) is widely integrated for a 3D graphics file format.

Also, the .CAD file comprises both 2D and 3D designs and data regarding materials, tolerances, and processes. The CAD file handles everything from design to production. 2D CAD files are usually known as drawings while 3D files are known as models or assemblies.

Not all formats are interchangeable. This makes CAD file format very crucial. You can only view some formats in some particular CAD applications. The format is the characteristics that define the CAD file. These formats are native and neutral.

Neutral formats such as IGES and STEP were industry standards most CAD platforms can read. Also, major CAD vendors produced native formats such as DWG, CATIA, and SOLIDWORKS. You need 3rd party CAD tools conversion to import these formats.

Importance of the .CAD File

CAD File

You must save a document as a file when using a computer to create one. This file usually has all important details associated with the document and as well contains information on how to visualize and process them.

Also, CAD file formats play a crucial role when CAD design is involved. You are designing a digital document when you use programs like SolidWorks or AutoCAD. The CAD file format specifies the program that helps you view the document. Also, it reveals what the document contains.

Every CAD system describes geometry using its own method. CAD files are capable of storing information for these processes. The two primary categories of the CAD file formats are Non-proprietary and proprietary.  Proprietary CAD file format features what you need from the original design without leaving anything behind. Also, this file format is ideal to share designs.

A non-proprietary CAD file is ideal for use when sharing the documents with external sources. Also, this file format isn’t exclusive to just one CAD program.

Properties the .CAD File can Store

Geometry representation

B-Rep and Meshes are the two commonest means of representing 3D data in CAD files. Also, B-Rep bodies are usually defined through a set of topological entities and geometrical entities. Geometrical entities are means of future visualization. Also, these entities store the data about geometric and dimensions properties of parts.

Furthermore, CAD file formats can vary based on their geometry representation. Topology is a factor of B-Rep. Bodies and elements are included in Toplological shapes. Geometry specifies the form of a body. On the other hand, topology stores connectivity data and specifies underlying geometry.

Product structure

Product structure refers to hierarchy of objects known as groups of objects that are interconnected. Most CAD software applications have a tree view at the left side of the screen. Users can easily expand the groups of this tree. To display or hide model elements, you need to tick the checkboxes.

Visual attributes representation

CAD files have the capability to specify visual attributes like line styles, colors, textures, and materials. Mesh and B-rep elements may have these features.  Considering visual attributes is necessary. These attributes won’t just enhance the appearance of the CAD model, but also clarify the functionality and structure. Furthermore, .CAD file format may vary based on the availability of a certain attribute and the way it supports. For example, colors may be chosen from a list of basic options or defined through RGB tuples.


.CAD files comprise metadata. These include Product and Manufacturing information (PMI), Object names and IDS, layers, and validation properties. Metadata carries out less features of the model. The ability of CAD files to transfer these data varies.

What are the Most Common File Formats?


CAD data usually travel between clients, investors, and contractors. It is crucial to integrated optimal CAD formats that can operate between existing software applications. Below are most common file extensions.

ACIS-SAT file format

This is a native format. It belongs to the ACIS geometric modeling kernel. Also, this kernel paves way for ACIS-SAT application. Also, the ACIS-SAT file format offers support to two extensions which are SAB (standard ACIS Binary) and SAT (Standard ACIS Text). The SAT enables the manual tweaking of the model contents. SAB, on the other hand, is more compact.

STL file format

Stereolithography (STL) file format is specially designed for 3D printing. However, it serves other purposes asides from 3D printing. It is extensively used in CAM workflows and laser scanning. Most multi-purpose CAD packages offer support to the STL.  Also, the CAD modeling tools support the STL file format. However, the absence of connectivity information results in low performance and inaccuracy.

STEP file format

STEP means Standard for the Exchange of Product model data). This file format comprises several Application Protocols (APs) which include AP 203 for assemblies and mechanical parts’ 3D designs. AP 242 is speculated for model based 3D engineering. The APs cover all primary aspects of manufacturing and design. Also, STEP file format is compatible with various 3D modeling, CAD, and CAM software applications.

VRML file format

VRML means Virtual Reality Modeling Language. This was the first 3D format specially designed to showcase 3D scenes on websites. Also, the .VRML file format allows visitors on the website to communicate with virtual objects. A plain text file is the commonest form of VRML. However, there is a gzip-compressed extension. Also, the VRML file format comes with sophisticated features like references to audio and keyframe-based animation.


We have gathered a lot of knowledge on what CAD files can offer users and their importance. Also, we have discussed most common file formats for CAD.