1.
KiCad EDA - Schematic Capture & PCB Design Software
https://www.kica
.org/

Open source EDA / electronics CAD software for Windows, macOS and Linux. Use schematic capture, create PCB designs and view them in 3D, all forever free.

2.
Affordable Easy-To-Use CAD Viewer and Converter - 3D-Tool
https://www.3d-too
.com/

Open, Measure and Convert CATIA, Siemens NX, Creo, SolidWorks, SolidEdge, Inventor, Rhino, JT, STEP, IGS, VDA, X_T, SAT [Free Trial Now]

3.
nanoCAD - CAD Software with native DWG for 2D design and 3D modeling
https://nanoca
.com/

nanoCAD - professional, cost-effective CAD Software with powerful 2D/3D modeling tools for viewing and drawing DWG files in engineering and architecture. Free download.

4.
Alibre | 3D CAD Software | 3D CAM Software | CNC Machines
https://www.alibr
.com/

Highest rated 3D CAD software for business on Capterra - it's powerful, easy to use, and affordable. 3D design and manufacturing suite. Hobby version available.

5.
Sweet Home 3D - Draw floor plans and arrange furniture freely
http://www.sweethome3
.com/

Free interior design software. Draw the plan of your home or office, test furniture layouts and visit the results in 3D.

8.
OpenFOAM | Free CFD Software | The OpenFOAM Foundation
https://openfoa
.org/

OpenFOAM is the leading free, open source software for computational fluid dynamics (CFD), owned by the OpenFOAM Foundation and distributed exclusively open source under the General Public...

9.
Free 3D models, CAD files and 2D drawings - TraceParts
https://www.tracepart
.com/en/

TraceParts is one of the world’s leading providers of 3D digital content for Engineering. The traceparts.com portal is available free-of-charge to millions of CAD users worldwide. It provides access to hundreds of supplier catalogs and more than 100 Million CAD models and product datasheets.