Native CAD interfaces
Direct support for the CAD formats listed here.
Siemens NX Viewer
Open Siemens NX and I-DEAS files
intuitive & practical 3D without CAD expertise
affordable & universal many 3D/2D interfaces
Modern, easy-to-use CAD viewer
Cost-effective CAD converter for all formats
The 3D-Tool Viewer opens Siemens NX and I-DEAS files without Siemens NX software.
The 3D-NativeCAD Converter converts Siemens NX and I-DEAS models to a wide range of formats such as STEP, IGES, JT, SAT, Parasolid X_T, STL, OBJ, 3DS, PLY, 3D-PDF, 3D-HTML, FBX, 3MF, and glTF.
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Stable, precise CAD data processing.
Windows support
Compatible with current Windows versions.
What are PRT files?
- The PRT file extension is used by several programs. In the CAD/CAM field, it refers to native 3D models from either Siemens NX or ›› Creo. Creo files can often be identified by a number after the file extension (*.prt.1, *.prt.2).
- PRT files from Siemens NX can contain 3D parts, 3D assemblies, 2D drawings, and Product Manufacturing Information (PMI).
- A Siemens NX assembly file is linked to at least one, but usually several, PRT parts and often other PRT assemblies.
- UGS developed the two CAD systems Unigraphics (today Siemens NX) and I-DEAS in 1978 and 1982 respectively. UGS was acquired by Siemens in 2007, and Siemens combined the two systems into today's Siemens NX.
PRT file versions
New Siemens NX releases appear regularly. Newer releases use version designations such as 2206, 2212, and 2306, where 2306, for example, stands for June 2023. The current version is 2512. (05/2026)
Older releases from 2019 to 2021 are designated Siemens NX 1847 through Siemens NX 2007. Before that, Siemens NX used simple version numbers from Siemens NX 1 through Siemens NX 12. Until 2001, the designations were UG/Unigraphics 3.0 through 18.0.
Since 2013, or Siemens NX 9, Siemens PLM Software has offered the software only as a 64-bit version. Support for MacOS was discontinued with Siemens NX 12.
I-DEAS and its file formats MF1, ARC, UNV, and PKG are still used, but mainly to maintain existing long-term projects and historical data, especially in the automotive, aerospace, and defense industries.
Additional native Siemens NX file formats
In contrast to most other CAD systems, NX has no individual file extensions for parts, assemblies and drawings.
Worth mentioning is the Parasolid modeling kernel used by Siemens NX. Parasolid X_T and X_B files are 3D exchange formats without a modification history, but are the first choice for exchanging 3D models between CAD/CAM programs with a Parasolid core such as Siemens NX, SolidWorks and Solid Edge.
The native I-DEAS formats MF1, ARC, UNV, and PKG are only partially supported by Siemens NX and require special import and conversion interfaces.
How do I open Siemens NX and I-DEAS files?
For native Siemens NX PRT data, a Siemens NX installation is typically used. Alternatively, the files can also be opened with CAD/CAM software that has a Siemens NX interface, for example in SolidWorks and Solid Edge.
Without an I-DEAS installation, the native I-DEAS formats MF1, ARC, UNV, and PKG generally require special import and conversion interfaces.
Although there are no free Siemens NX and I-DEAS viewers available, CAD viewers are an affordable alternative compared to a full CAD system. The 3D-Tool CAD viewer opens all of the Siemens NX and I-DEAS file formats listed above and can be tested free of charge for 14 days.
How do I convert Siemens NX and I-DEAS files?
Without CAD software with a Siemens NX or I-DEAS interface, the design must be exported to a common 3D exchange format, such as STEP.
Converting Siemens NX and I-DEAS to STEP is also possible with a 3D converter. The 3D-NativeCAD Converter in 3D-Tool Premium converts native Siemens NX and I-DEAS models and models from many other CAD systems reliably into the standard 3D exchange formats STEP, IGES, SAT, and Parasolid X_T.
Test the Siemens NX Viewer and Siemens NX Converter for free
3D-Tool is a CAD Viewer with many native CAD interfaces, including Siemens NX and I-DEAS. 3D-Tool provides professional measurement, draft analysis, and wall thickness analysis.
- Open Siemens NX and I-DEAS files, add dimensions and comments, and publish them for the 3D-Tool Free Viewer or as 3D PDF
- Open Siemens NX and I-DEAS files and save them as STL, 3DS, PLY, WRL, or OBJ
- Convert Siemens NX and I-DEAS files to STEP, IGES, SAT, X_T, and JT
- Convert Siemens NX and I-DEAS models to 3D product visualizations such as 3D-HTML, FBX, Collada, 3MF, and glTF
Free, no-obligation 14-day trial with all features, the Siemens NX interfaces, and the 3D-NativeCAD Converter. The trial key activates all 3D interfaces, including CATIA, Siemens NX, SolidWorks, Inventor, STEP, SAT, and Parasolid.
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